President Barack Obama pledged the full resources of the U.S. government to assist the community of Moore, Okla., in its recovery following devastating tornadoes that hit the town on Monday. 

“The people of Moore should know that their country will remain on the ground -- for them, beside them -- for as long as it takes,” Obama said in a statement Tuesday morning at the White House, calling the storm “one of the most destructive tornadoes in history.” Obama said the prayers of the nation are with the people of Oklahoma, adding “as a nation, our full focus right now is on the urgent work of rescue, and the hard work of recovery and rebuilding that lies ahead.”

Noting that process will be long, the president assured that those affected “will not travel that path alone, your country will travel it with you.” 

The president said that he had spoken with Oklahoma Gov. Mary Fallin, R, to coordinate the federal government’s assistance to Moore, and had dispatched FEMA Director Craig Fugate to Oklahoma. Obama also signed a disaster declaration on Monday evening opening avenues for federal assistance to those affected by the hurricane. 

Moore, a town which had also suffered a serious tornado in 1999, was damaged heavily during last night’s storm. The president said that it was too early to assess the extent of the damage, death and injuries.

“But if there is hope to hold on to, not just in Oklahoma but around the country, it's the knowledge that the good people there and in Oklahoma are better prepared for this type of storm than most. And what they can be certain of is that Americans from every corner of this country will be right there with them, opening our homes, our hearts to those in need.  Because we're a nation that stands with our fellow citizens as long as it takes.”

Obama urged Americans who are interested in helping the tornado victims to donate to the American Red Cross, which he said is already on the ground in Moore.

Updated 5:31 p.m. - Mitt Romney reiterated his opposition to same-sex marriage on Wednesday but declined to condemn President Obama's endorsement of gay marriage, noting the sensitivity of the issue.

Following a campaign speech in Oklahoma that focused primarily on energy, jobs and the economy, the presumptive Republican nominee reaffirmed his opposition to same-sex marriage in light of Obama's announcement today.

"I have the same view on marriage that I had when I was governor," he said. "I believe marriage is a relationship between a man and a woman."

It was an opinion that Romney had voiced earlier in the day to television affiliates in Colorado, when the former Massachusetts governor faced questions amid growing speculation that Obama would announce his support for same-sex marriages.

But while Romney's position contrasted with Obama's, he declined to sharply criticize the president -- saying he would leave it up to the media to parse out Obama's "evolution" on the issue.

"This is a very tender and sensitive topic as are many social issues, but I have the same views I've had since running for office," he said.

Earlier: Romney renews opposition to same-sex marriage

Romney has previously backed certain benefits for gay couples -- for instance, the right to visit with a sick partner in the hospital -- but said each state should be free to determine their own laws.

It was a markedly more subdued reaction by Romney compared to some conservatives, who condemned Obama's support for gay and lesbian couples' ability to marry.

"The announcement today by President Obama should come as no surprise to the American public," said Rick Santorum, Romney's erstwhile conservative challenger in the Republican primary. "President Obama has consistently fought against protecting the institution of marriage from radical social engineering at both the state and federal level."

"While President Obama has played politics on this issue, the Republican Party and our presumptive nominee Mitt Romney have been clear," said Republican National Committee Chairman Reince Priebus. "We support maintaining marriage between one man and one woman and would oppose any attempts to change that."

Obama: 'I think same-sex couples should be able to get married'

Former Arkansas Gov. Mike Huckabee, who passed up an opportunity to run for president in 2012 but maintains a reservoir of support among social conservatives, also condemned Obama's announcement.

"Obama, Pelosi and the Democrats have been a complete failure on economic issues so now they are going to focus on issues that will rile up their base," Huckabee wrote in a statement released by his PAC. "Well, Mr. President it's going to rile up our folks also. Men and women who support traditional marriage."

A spokeswoman for Texas Gov. Rick Perry said: "Election year politics will never change Gov. Perry's unwavering commitment to the sanctity of marriage, defined as a union between one man and one woman. He is proud of North Carolina voters who last night elected to enshrine that definition in their constitution, joining Texas and an increasing number of states in the ongoing effort to defend marriage. Once again, it's clear that President Obama's political ideology doesn't line up with the will of the voters."

Romney campaign reckons with gay rights after aide's exit

But for as many conservative voices decried the president's announcement on Wednesday, many more Republicans kept their silence, including most GOP leaders in both houses of Congress.

"Well I think he made his position pretty clear. I've always believed that marriage is between a man and a woman," House Speaker John Boehner said on the Fox Business Network. Boehner said he wasn't familiar with a proposed amendment to the Constitution to define marriage, but said Obama's announcement was a "very controversial" notion.

By contrast, Democratic supporters of the president could, for the most part, hardly contain their jubilation for Obama's decision.

"Today marks progress for the civil rights of LGBT Americans and all Americans," said House Speaker Nancy Pelosi (D-CA). "With President Obama's support, we look forward to the day when all American families are treated equally in the eyes of the law."

New York Sen. Kirsten Gillibrand, who endured her own shift toward supporting gay marriage, also hailed the president's announcement as "a watershed moment in American history."

CUSHING, OK -- Surrounded by massive green pipes that will eventually make up part of the Keystone oil pipeline, President Obama today praised the decision by TransCanada to move forward with the southern portion of the controversial energy project.

"Right now, a company called TransCanada has applied to build a new pipeline to speed more oil from Cushing to state-of-the-art refineries down on the Gulf Coast," Obama said in Cushing, OK. "And today, I am directing my administration to cut through red tape, break through bureaucratic hurdles, and make this project a priority."

Obama also used the occasion to announce that he is instructing federal agencies to expedite the permitting process for the Cushing pipeline as well as an executive order for agencies to overall issue permits faster for “vital infrastructure projects.”

Mandel Ngan / AFP - Getty Images

President Obama talks about his administration's energy efforts on Thursday in Cushing, Okla.

Since news of this announcement broke on Tuesday, Republicans have slammed the move as an attempt to take ownership of a process over which the White House has no actual authority.

“The president can take credit for having nothing to do with the bottom half of this pipeline, and the fact is is there's only one permit that requires his approval because it crosses our national boundaries and that's the keystone decision on the upper half of this," House Speaker John Boehner (R-OH) said at a press conference on Capitol Hill.

Republicans have been vocal in their criticism of the Obama administration for not moving forward with the full pipeline; the administration declined earlier this year to approve a permit request that would have allowed for the construction of the full, transnational oil pipeline.

Obama said in Cushing that he would continue pushing for oil exploration and development, but he would seek to "do it in a way that protects the health and safety of the American people."

"We don't have to choose between one or the other," he said, "We can do both."

But the White House on Wednesday provided an unclear picture of which agencies specifically would have authority to expedite the procedure for the TransCanada route and other pipelines.

Asked during a flight from Washington, D.C. to Nevada, where the president spoke earlier Wednesday, press secretary Jay Carney told reporters, “I just don’t have those details handy for you” when asked which agencies are involved in such processes.

Senior administration officials were later asked the same question on a conference call, as a reporter mentioned the Department of Fish and Wildlife and the Army Corps of Engineers as two agencies that might be involved.

One official said that permitting and review requirements would depend on the specific route and details of each pipeline plan but that “the agencies you suggested are in line with our best estimate.”

After his speech in Cushing, President Obama flew to Columbus, Ohio to make a speech on energy research and development at Ohio State University.

Michael O'Brien contributed

TULSA, Okla -- Status update: Yup, Herman Cain is still singing.

The grinning former presidential candidate on Monday treated Newt Gingrich supporters at a Tulsa pizza parlor to a booming rendition of "America the Beautiful" before launching into his case for the former speaker of the House.

"Even though I am no longer pursuing the position of president, I am still on a mission and that mission is to make sure that we get the right person in the White House and that person is former Speaker Newt Gingrich in order to help save America," he told the crowd of about 100. "That's why I am doing what I'm doing."

(Although the rally was held at a downtown Tulsa pizza joint, the onetime pie purveyor did not sample any of the goods.)

Heading into the Oklahoma primary, Cain joined former home state congressman J.C. Watts and Gingrich's daughter Jackie to promote the candidate's $2.50 gas plan. Watts predicted a primary struggle at least into May and said that Gingrich will continue to accumulate delegates after Super Tuesday.

"We think we're still in the hunt, and the voters are going to be good to us not just tomorrow but as we continue on," Watts said. 

Cain, himself a longtime radio host, spoke briefly to NBC News after the event about the exodus of at least eight advertisers from Rush Limbaugh's radio show.

"They would have to make that call," Cain said. "I just know that advertisers make their decisions about who they want to support and not support, but I don't think it's going to hurt the Rush Limbaugh show."

Asked if Limbaugh's comments about Georgetown Law student Sandra Fluke, who has lobbied the Catholic university to cover birth control under its student insurance plans, had hurt the GOP, Cain offered a flat "no."

"No, I don't think they hurt the party because Rush Limbaugh is not running for anything, so I don't think they hurt the party at all," he said.

On Tuesday March 6, 11 states across the country -- Alaska, Georgia, Idaho, Massachusetts, North Dakota, Ohio, Oklahoma, Tennessee, Vermont, Virginia, and Wyoming -- will hold contests that will award a combined 424 delegates. That’s more than any other one day this Republican primary season. Up until now, there have been 12 contests (in some form or fashion), with Mitt Romney winning seven of them, Rick Santorum four, Newt Gingrich one, and Ron Paul zero. NBC’s current delegate count stands at Romney 119, Gingrich 30, Santorum 17, Paul 8.

The GOP presidential candidates have different strategies and strongholds in these 11 contests. Romney hopes to lock down his home state of Massachusetts, Vermont, and Virginia (where only he and Paul are on the ballot). Santorum is expecting wins in Oklahoma and Tennessee. Gingrich has focused on his home state of Georgia. And Paul has concentrated on the caucuses in Alaska, Idaho, and North Dakota. The biggest prize is Ohio, where all the candidates -- except for Paul -- have campaigned. But more than anything else, Super Tuesday is a math race: Which candidate can rack up the most delegates from these 11 states? Note that many of these contests award delegates proportionally, so a second-place (or even third place) finish can get you delegates.

Click here to read the NBC News Super Tuesday Guide, complete with analysis of the candidates’ strategies, ad spending, candidate travel, history of Super Tuesday – when and why they’ve mattered, and a complete state-by-state breakdown of the delegates at stake, rules, procedures, poll opening and closing times, and full results so far.