"I find it troubling and revealing that the world around us is going to hell," he added, "and the president takes no responsibility."
Romney had a long list of criticisms of the Obama administration's actions abroad. In particular, Romney ripped Obama for saying that ISIS, aka the Islamic State, was geographically "contained" just before last week's terrorist attacks in Paris, France.
"Once again, you have a president not acknowledging that what he told us was wrong," Romney said. "He told us that ISIS was contained and he was wrong. He initially told us that he didn't have a strategy to deal with ISIS, then he tells us that he has a tactical approach. And his approach has not worked."
Romney even offered a prediction that Obama could go down as one of the worst national-security presidents in history.
"I just think that on the issue of foreign policy -- and [protecting] America and America's interests, and the interest of freedom secure and strong -- the president's been a disaster," he said. "I think he may go down in history as one of the very worst foreign-policy presidents in American history."
He added: "And the consequence of that is loss of life. The consequence of that is the loss of freedom."
Some members of the Republican establishment, worried about the rise of Donald Trump and Ben Carson, have reportedly discussed trying to draft Romney into the 2016 race. But Romney batted down that speculation again during his "Today" interview.
"I've said it. I'll say it again today, which is: I'm not running," Romney said, shaking his head. "I'm not planning on running."
For more on Mitt Romney, scroll through the gallery below:
Mitt Romney and Barack Obama, 2012 election
Mitt Romney: Obama is among 'the very worst foreign-policy presidents in American history'
Republican presidential nominee Mitt Romney, left is greeted by President Barack Obama before the start of the third presidential debate at Lynn University, Monday, Oct. 22, 2012, in Boca Raton, Fla. (AP Photo/David Goldman)
Moderator Candy Crowley, center, applauds as President Barack Obama, right, shakes hands with Republican presidential nominee Mitt Romney during the second presidential debate at Hofstra University, Tuesday, Oct. 16, 2012, in Hempstead, N.Y. (AP Photo/Pool-Michael Reynolds)
FILE - In this June 22, 2012 file photo, President Barack Obama speaks at a conference in Orlando, Fla. On health care Obama's position is clear, as is that of his Republican opponent, former Massachusetts Gov. Mitt Romney. Obama defends his federal health care overhaul and Romney opposes it. But come next week, when the Supreme Court rules on the constitutionality of the law, both sides are certain to scramble for political gain no matter the outcome. (AP Photo/Carolyn Kaster, File)
FILE - In this June 21, 2012 file photo, Republican presidential candidate, former Massachusetts Gov. Mitt Romney speak Orlando, Fla. The presidential race enters the sultry summer _ a final lull before a sprint to Election Day _ with President Barack Obama and Republican Mitt Romney neck and neck and no sign that either can break away. Both sides have money concerns _ for all the flood of cash _ as well as political worries. (AP Photo/Charles Dharapak)
President Barack Obama listens as Republican presidential nominee Mitt Romney answers a question during the first presidential debate at the University of Denver, Wednesday, Oct. 3, 2012, in Denver. (AP Photo/Pool, Rick Wilking)
President Barack Obama speaks as Republican presidential nominee Mitt Romney listens during the second presidential debate at Hofstra University, Tuesday, Oct. 16, 2012, in Hempstead, N.Y. (AP Photo/Eric Gay)
President Barack Obama, right, and Republican presidential candidate, former Massachusetts Gov. Mitt Romney, participate in the second presidential debate, Tuesday, Oct. 16, 2012, at Hofstra University in Hempstead, N.Y. (AP Photo/Carolyn Kaster)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney and President Barack Obama attend the 67th annual Alfred E. Smith Memorial Foundation Dinner, a charity gala organized by the Archdiocese of New York, Thursday, Oct. 18, 2012, at the Waldorf Astoria hotel in New York. (AP Photo/Charles Dharapak)
In this Oct. 16, 2012 file photo, Republican presidential candidate, former Massachusetts Gov. Mitt Romney and President Barack Obama spar during the second presidential debate at Hofstra University in Hempstead, N.Y. (AP Photo/Charlie Neibergall, File)
FILE - In this Oct. 22, 2012 file photo, Republican presidential candidate, former Massachusetts Gov. Mitt Romney and President Barack Obama walks past each other on stage at the end of the last debate at Lynn University in Boca Raton, Fla. Obama and Romney courted the Hispanic community during the campaign, but only spent $ 22.8 million on advertising on Spanish language television, from a total cost of $ 355 million on television advertizing in 10 states, according to the Hispanic Chamber of Commerce of the United States on Friday, Nov. 16, 2012. (AP Photo/Pablo Martinez Monsivais, File)
Campaign signs for both President Barack Obama, and his challenger, Republican presidential candidate, former Massachusetts Gov. Mitt Romney are seen in yards outside Evans City, Pa., Friday, Nov. 2, 2012. In the final days of the presidential campaign, Romney is making a concerted push into Pennsylvania, aided by outside political groups that are spending millions in last minute ads in the state to help erode Obamaâs 2008 support. Polling shows Obama holding on to a 4 or 5 percentage point lead over Romney, but the trend has been in Romneyâs favor. (AP Photo/Keith Srakocic)
US President Barack Obama arriveS on stage after winning the 2012 US presidential election November 7, 2012 in Chicago, Illinois. Obama swept to re-election, forging history again by defying the dragging economic recovery and high unemployment which haunted his first term to beat Republican Mitt Romney. AFP PHOTO / Saul LOEB (Photo credit should read SAUL LOEB/AFP/Getty Images)
Republican presidential candidate and former Massachusetts Gov. Mitt Romney arrives to his election night rally, Wednesday, Nov. 7, 2012, in Boston. President Obama defeated Republican challenger former Massachusetts Gov. Mitt Romney. (AP Photo/Elise Amendola)