President Clinton said Friday he was sorry about his affair with Monica Lewinsky, apologizing for the first time in the face of growing criticism among even close Democratic allies who are pressing for a public reprimand of his conduct.

The president has been under increasing pressure to apologize for his actions since his Aug. 17 remarks where he did not do so.

"I made a bad mistake," Clinton said. "It's indefensible and I'm sorry about it."

Clearly uncomfortable addressing the matter on an international stage, Clinton spoke hours after Democratic Sen. Joseph Lieberman of Connecticut, in a stern speech on the Senate floor, called the president's actions immoral and harmful to the nation.

"The transgressions the president has admitted to are too consequential for us to walk away and leave the impression for our children and our posterity that what President Clinton acknowledges he did within the White House is acceptable behavior for our nation's leader," said Lieberman, whose words drew praise from other Democrats.

Some sort of public rebuke is called for, he added, noting Congress at some point should express its disapproval through a resolution, censure or reprimand. But he said any such action is premature until Independent Counsel Kenneth Starr reports on his assessment of whether Clinton had committed any impeachable offenses and the White House has a chance to respond to it.

Clinton, in his televised Aug. 17 speech, said he regretted his relationship with Lewinsky, a former White House intern half his age, and the months that he misled his family and the American people. Lawmakers of both parties criticized Clinton for not directly apologizing.

One of those critics, Colorado Gov. Roy Romer, the Democratic Party chairman, said Friday that Clinton's most recent, most direct statement about being sorry is "helpful."

"I think he's been saying that with other words. He's had difficulty getting it out," Romer said.

At a Moscow news conference Wednesday with Russian President Boris Yeltsin, Clinton for the first time said publicly that he had made a mistake by engaging in an affair with the former White House intern. He also was more direct than previously in admitting that he had sought forgiveness.

"I have acknowledged that I made a mistake, said that I regretted it, asked to be forgiven, spent a lot of very valuable time with my family in the last couple of weeks and said I was going back to work," Clinton said.

White House press secretary Mike McCurry said afterward that the president was taking a "one day at a time" approach to managing the crisis.

"I think the president clearly does not believe that one conversation, one statement, one speech is going to be sufficient in addressing this matter the way he wants to, and he intends to keep addressing it both personally and - to the degree he needs to - publicly as he sees fit," McCurry said.

During a photo session with Irish Prime Minister Bertie Ahern, Clinton was asked Friday to respond. "I can't disagree with anyone else who wants to be critical of what I've already acknowledged is inappropriate," he said.

"There's nothing that he (Lieberman) or anyone else could say in a personally critical way that I don't imagine I would disagree with since I have already said it myself, to myself, and I'm very sorry about it but there's nothing else I can say," Clinton said.

On the Senate floor Thursday, two other prominent Democratic senators - New York's Daniel Patrick Moynihan and Nebraska's Bob Kerrey - joined Lieberman in sternly denouncing Clinton's relationship with Lewinsky and his handling of the affair's aftermath.

Lieberman said Clinton had "compromised his moral authority," damaged his credibility and complicated the efforts of parents seeking to instill "values of honesty" in their own children.