President Obama tells volunteers in Dallas that despite challenges in implementing the Affordable Care Act, families in Texas will have access to affordable, high quality health insurance, vowing "to get this done." (Reuters)

President Obama apologized Thursday to Americans who are losing their health insurance despite his repeated promises that they wouldn’t, an unusual act of contrition for a president who has come under heavy criticism for misleading the public.

“I am sorry that they, you know, are finding themselves in this situation, based on assurances they got from me,” Obama said in an interview with NBC News. “We’ve got to work hard to make sure that they know we hear them and that we’re going to do everything we can to deal with folks who find themselves in a tough position as a consequence of this.”

The president said he had asked his staff to see whether there was an administrative fix to preserve insurance for some Americans who may have lost their coverage and do not qualify for subsidies that would make new policies affordable.

“I’ve assigned my team to see what we can do to close some of the holes and gaps in the law,” he said, “because, you know, my intention is to lift up and make sure the insurance that people buy is effective — that it’s actually going to deliver what they think they’re purchasing.”

A White House official, who spoke on the condition of anonymity, said the president’s policy team has been investigating the possibility of an administrative solution since the problem surfaced as a significant issue late last month.

The problem has arisen for those who buy insurance on the individual marketplace, a number that totals between 12 million and 15 million people. About half of those are probably being adversely affected by the Affordable Care Act, the aide said.

Presidents rarely say “I’m sorry” in public, even when acknowledging missteps. Obama’s most recent unvarnished apology came in February of last year when he told Afghan President Hamid Karzai that he was sorry for the involvement of U.S. service members in the burning of copies of the Koran, an incident that provoked widespread protest in the country at a delicate time in the war and in his own reelection campaign.

Thursday’s apology, coming at a time when the president and his administration are under intense criticism over the rollout of the health-care law, highlights the extent to which it has become a political liability for the White House. On Tuesday, President Obama’s approval rating dipped below 40 percent for the first time in two years, according to a daily tracking poll by Gallup.

The fact that Obama had said repeatedly that insured Americans would not have to change plans has become a new line of attack for congressional Republicans and an Internet meme, as news organizations have strung together video clips of the president’s comments on the subject over the past four years.

In a speech before the American Medical Association in June 2009, for instance, Obama said: “If you like your health-care plan, you’ll be able to keep your health-care plan, period. No one will take it away, no matter what.”

The disconnect between Obama’s assurances and the reality for some consumers emerged last month as a flood of people learned that they could not keep plans they had signed up for on the individual market. Although this group represents a small fraction of the total number of insured Americans — about 5 percent — their stories garnered national attention and provided fodder to opponents of the law.

On Thursday, for example, the conservative group Americans for Prosperity launched a $1 million ad campaign targeting four House members, including two Democrats who voted for the health-care law. One ad criticizes Rep. Ann Kirkpatrick (D-Ariz.) for helping make the law a reality. “Now Arizonans are losing the health-care plans they love,” the narrator says. “The doctors they love. And millions remain uninsured.”

Obama defended the law several times over the course of the NBC interview, saying many of the people now receiving cancellation notices were in “subpar plans” and would probably benefit from new options — although they aren’t able to see them now because of continued problems with the Web site

“The majority of folks will end up being better off, of course. Because the Web site’s not working right, they don’t necessarily know it right” now, he said. “Keep in mind that most of the folks who . . . got these cancellation letters, they’ll be able to get better care at the same cost or cheaper in these new marketplaces.”

And although the president apologized for the fact that “we weren’t as clear as we needed to be in terms of the changes that were taking place,” he only did so after Chuck Todd, NBC’s chief White House correspondent, pressed him on the point.

Over the past two weeks, the president and his aides have emphasized that the cancellations stemmed largely from decisions by insurers, rather than from the law.

In a speech in Boston on Wednesday, Obama said that letting people keep their plans “was part of the promise we made” but that part of the law’s purpose is to help consumers upgrade their plans. On Monday night, he suggested that the promise really applied only to people who bought their plans before the health-care overhaul was enacted.

Several insurance officials, who asked to remain anonymous because of the sensitivity of the issue, said in interviews that the way the regulations were written after the law’s passage gave them little choice but to issue the cancellations. They said that the old policy could continue in effect only if very few changes were made and the price remained about the same.

The White House official said the president — who spent more than two hours Wednesday meeting with Democratic senators who are concerned about the law’s implementation — felt responsible for the effect on both the Americans now being adversely affected and “for the people who voted for it.”

Republicans such as Senate Minority Leader Mitch McConnell (Ky.) voiced little sympathy for the president after his interview aired Thursday.

“If the president is truly sorry for breaking his promises to the American people, he’ll do more than just issue a half-hearted apology on TV,” McConnell said in a statement. “A great place to start would be to support the [Wisconsin GOP Sen. Ronald H.] Johnson bill that would allow Americans to do what the president promised in the first place: keep the plan they have and like.”

Zachary A. Goldfarb and Scott Wilson contributed to this report.