As two of his key nominees withdrew from his administration because of tax wrongdoings, United States President Barack Obama [Images] admitted that he has committed mistakes.

"I think I screwed up. I take responsibility for it and we're going to make sure we fix it so it doesn't happen again," Obama told CNN in an interview.

In a setback to his two-week old administration, Tom Daschle and Nancy Killefer on Tuesday withdrew respectively from their nominated posts of Secretary of Health and Human Services and White House's Chief Performance Officer. Both of them face tax related issues as they have failed to pay their taxes.

In a series of interviews to the US electronic media, Obama took the responsibilities of the mistake that his team has made in vetting individuals on whom questions are being raised.

"What became clear to me is that we can't send a message to the American people that we've got two sets of rules: one for prominent people and one for ordinary people. So I consider this a mistake on my part and one that I intend to fix and correct and make sure that we're not screwing up again," the President said in another interview with FOX News.

The series of interviews to five major US television networks, which were primarily meant to drum up support for his economic stimulus package, ended up in Obama responding to questions related to the first controversies of his administration.

"This is a mistake, probably not the first one I'm going to be making in this office. But what I'm absolutely committed to doing is fixing it, getting a highly-qualified Health and Human Services Secretary, and then making sure that we start providing some health-care relief to families who so desperately need it," he told Chris Wallace of Fox News.

Responding to a query of CNN's Anderson Cooper, Obama said, "Well, I think my mistake is not in selecting Tom originally, because I think nobody was better equipped to deal both with the substance and policy of health care. He understands it as well as anybody, but also the politics, which is going to be required to actually get it done."

"I think what happened was that Tom made an assessment that having made a mistake on his taxes that he took responsibility for, it was going to be too much of a distraction in trying to lead what is going to be a very heavy lift, trying to deliver health care," he added.