Idaho Sen. Larry Craig resigned from his Republican Senate seat Saturday, bowing to pressure from Republicans to step down after his arrest and guilty plea in a sex scandal.
"It is with sadness and deep regret that I announce that it is my intent to resign from the Senate, effective Sept. 30," Craig said, appearing with his wife, Suzanne, at a press conference in Boise, Idaho.
The resignation comes after reports that Craig pleaded guilty Aug. 1 to a reduced misdemeanor charge from his arrest June 11 in a men's room at the Minneapolis-St. Paul International Airport.
The three-term Republican senator did not admit wrongdoing, but apologized for being unable to serve the rest of his term to pursue legal options.
"I apologize for what I have caused. I am deeply sorry," Craig said. "I have little control over what people choose to believe but clearly my name is important to me and my family is so very important also."
Idaho Gov. C.L. Butch Otter will appoint Idaho Lieutenant Governor James E. Risch to serve out the remainder of Larry Craig's term.
Risch, the lieutenant governor, served for seven months as governor last year after former Gov. Dirk Kempthorne was named interior secretary. Risch had said earlier he was interested in Craig's Senate seat if Craig did not seek re-election in 2008.
While Republicans urged Craig to step down earlier in the week, GOP leaders were quick to wish Craig well after his announcement.
President Bush called Craig after he heard the news of his resignation.
"Sen. Craig made the right decision for himself, his family, his constituents, and the United States Senate. After the president heard the news he called Sen. Craig and he said he knew it was a difficult decision and wished him well," said Scott Stanzel, a White House spokesman.
Senate Minority Leader Mitch McConnell issued a statement of support.
"Senator Larry Craig made a difficult decision, but the right one. It is my hope he will be remembered not for this, but for his three decades of dedicated public service," McConnell said in a statement.
Craig has been out of public view since Tuesday, when he declared defiantly at a Boise news conference: "I am not gay. I have never been gay." But Republican sources in Idaho said he spent Friday making calls to top party officials, including the governor, gauging their support.
Asked Friday at the White House if the senator should resign, President Bush said nothing and walked off stage.
Republican officeholders and party leaders maintained a steady drumbeat of actions and words aimed at persuading Craig to vacate his Senate seat.
GOP lawmakers, hoping to get the embarrassment to the party behind them quickly, stripped Craig of leadership posts on Wednesday, one day after they called for an investigation of Craig's actions by the Senate Ethics Committee. Craig complied with the request.
With his wife, Suzanne, at his side, he said he had kept the incident from aides, friends and family and later pleaded guilty "in hopes of making it go away."
Craig, 62, has represented Idaho in Congress for more than a quarter-century and was up for re-election next year.
Senate Minority Leader Mitch McConnell called Craig's conduct "unforgivable" and acknowledged that many in the rank and file thought Craig should resign.
The contest for control of the next Senate was already tilted against Republicans, who must defend 22 of 34 seats on the ballot next year, before the Craig scandal and the announcement from Virginia Sen. John Warner that he would not seek re-election.
With a GOP candidate other than Craig, Republicans would stand a much better chance of keeping his Idaho seat in 2008.
Idaho is one of the nation's most reliably Republican states. The GOP controls the statehouse and all four seats in Congress, and Bush carried the state in 2004 with 68 percent of the vote.
On Thursday, the Minneapolis airport authorities released a tape recording of Craig's interrogation minutes after he encountered a plainclothes officer in an adjacent stall in an airport restroom.
Craig and airport police Sgt. Dave Karsnia disagreed about virtually everything that had occurred — including whether there was a piece of paper on the floor of the stall and the meaning of the senator's hand gestures.
Craig denied that he had used foot and hand gestures to signal interest in a sexual encounter.
"I'm not gay. I don't do these kinds of things," Craig told the officer. "You shouldn't be out to entrap people."
FOX News' Major Garrett and The Associated Press contributed to this report.