Mitt Romney harshly criticized President Obama's leadership Sunday morning, saying that Obama's "fundamental dishonesty" in promoting his health care law "has really put in peril the whole foundation of his second term."

Romney also rejected comparisons between Obamacare and the law he enacted in Massachusetts as governor when asked by NBC's David Gregory on "Meet the Press" about Obama's appearance in the Bay State to promote the health care law last week.

Romney took issue with the president's repeated promise over the past three years that "if you like your health insurance, you can keep it," a promise that has proven to be false.

"The key, I think, that has really undermined the president's credibility in the hearts of the American people," Romney said, "is that he went out, as a centerpiece of his campaign and as a centerpiece of Obamacare over the last several years, saying time and time again that fundamental to his plan was the right people would have to keep their insurance plan, and he knew that was not the case."

Obama could have known that people would lose insurance under the reform law, Romney claimed, by looking at the experiences of Romney's law in Massachusetts. It was a mistake, Romney said, for Obama to think to that he could "impose" a similar plan on the country, doing so "in a dishonest way."

"Obamacare barely made it through Washington, as you know," said Romney. "There’s no question in my mind that, had the president been truthful and told the American people that millions would lose their insurance and millions more would see their premiums skyrocket ... there would have been such a hue and cry against it, it would not have passed.”

"We’ve got to have a president that can lead, and right now he’s not doing so," Romney said of Obama.

Romney also noted that health insurance in Massachusetts "is more expensive than anywhere in the country," and predicted that "You’re going to see as a result of Obamacare costs going up dramatically across the country.”