"I did nothing wrong at the Minneapolis airport," he said at a news conference with his wife, Suzanne, at his side.
Craig's defiant news conference came as Senate Republican leaders in Washington called for an ethics committee review into his involvement in a police sting operation this summer in the airport men's room.
Craig is the first sitting U.S. Senator in recent memory to have his own mug shot, reports CBS News correspondent Sharyl Attkisson.
"In the meantime, the leadership is examining other aspects of the case to see if additional action is required," Sen. Mitch McConnell and other top GOP lawmakers said in a written statement obtained by The Associated Press.
Earlier, the private group Citizens for Responsibility and Ethics filed a complaint with the ethics committee seeking an investigation into whether Craig violated Senate rules by engaging in disorderly conduct.
Republican leaders also are "examining other aspects of the case to see if additional action is required," Sen. Mitch McConnell and other top GOP lawmakers said in a written statement obtained by The Associated Press.
They released the statement shortly before Craig's scheduled appearance before television cameras in Boise, his first public comment since confirming his guilty plea to a misdemeanor charge of disorderly conduct.
Craig entered his plea several weeks after an undercover police officer in the Minneapolis arrested him and filed a complaint that said the three-term senator had engaged in actions "often used by persons communicating a desire to engage in sexual conduct."
The bathroom incident in the Minneapolis airport occurred on June 11. Craig signed his plea papers on Aug. 1, and word of the events surfaced on Monday. The senator issued a statement Monday night that said, "In hindsight, I should have pled not guilty."
The statement by McConnell and other members of the GOP leadership was brief - and contained no words of support for their veteran colleague.
"This is a serious matter. Due to the reported and disputed circumstances, and the legal resolution of this serious case, we will recommend that Senator Craig's incident be reported to the Senate Ethics Committee for its review," they said.
The statement did not specify what other actions might be under consideration.
The married Craig, 62, has faced rumors about his sexuality since the 1980s, but allegations that he has engaged in gay sex have never been substantiated. Craig has denied the assertions, which he calls ridiculous.
Back in 1982, CBS News broke stories on a Congressional page sex scandal. The story didn't implicate Craig, or any other member of Congress by name, but Craig was the only one to issue an immediate denial, reports Attkisson .
Twenty-five years later he's in the same boat. Tuesday he said his only transgression was keeping the arrest to himself.
The arrest changes that dynamic, said Jasper LiCalzi, a political science professor at Albertson College of Idaho in Caldwell, Idaho. He cited the House page scandal that drove Florida Rep. Mark Foley from office.
"There's a chance that he'll resign over this," LiCalzi said. "With the pressure on the Republican Party, he could be pressured to resign. If they think this is going to be something that's the same as Mark Foley - the sort of 'drip, drip, drip, there's more information that's going to come out' - they may try to push him out."
Already Craig has stepped down from a prominent role with Mitt Romney's presidential campaign. He had been one of Romney's top Senate supporters, serving as a Senate liaison for the campaign since February.
"He did not want to be a distraction and we accept his decision," said Matt Rhoades, a Romney campaign spokesman.
According to a Hennepin County, Minn., court docket, Craig pleaded guilty to a disorderly conduct charge on Aug. 8, with the court dismissing a charge of gross misdemeanor interference to privacy.
The court docket said Craig paid $575 in fines and fees and was put on unsupervised probation for a year. A sentence of 10 days in the county workhouse was stayed.