An American man imprisoned for sneaking into the home of detained Burma democracy leader Aung San Suu Kyi flew out of the country Sunday after a visiting U.S. senator won his release.

John Yettaw of Falcon, Mo., was headed to Bangkok, Thailand, on a military plane with Sen. Jim Webb of Virginia, who secured his freedom Saturday with a plea to Burma's ruling military junta. Yettaw was convicted last week of breaking the terms of Suu Kyi's house arrest by swimming to her lakeside home in early May and staying for two days.

Webb was also allowed a rare meeting with Suu Kyi, who is tightly restricted in her house arrest.

The concessions to Webb during his visit -- the first by a member of the U.S. Congress in more than a decade -- could presage a new approach by Washington toward the military government, which it has shunned.

But some of the junta's critics charged that Webb's trip will hurt the cause of democracy in Burma, which has been under military control since 1962.

Suu Kyi, who has been detained for 14 of the last 20 years, was sentenced by a court to three years in prison with hard labor for violating her house arrest as a result of Yettaw's intrusion, but the punishment was reduced to 18 months of house arrest by the junta's chief, Senior Gen. Than Shwe.

Two female companions who live with her received the same sentence.

Yettaw, 53, was also convicted of an immigration violation and of swimming in a restricted zone, and received a total of seven years in prison with hard labor. He reportedly suffers from diabetes, epilepsy and asthma and was hospitalized for a week during the trial after suffering seizures.

Yettaw said he made the visit to Suu Kyi's house because he had a vision that she was at risk of harm from assassins.

"I believe he was probably motivated by good intentions but he committed a very serious violation in this country," Webb said at a brief news conference just before leaving Burma. "It was a good gesture from your country to our country for humanitarian reasons to allow him to return to his family."

Yettaw did not appear at the news conference.

Yettaw has been held in Insein, Burma's largest prison, which is notorious for torture and other abuses of both political prisoners and ordinary criminals.

His lawyer has said his client was well-treated, though he fell ill while incarcerated.

"If it's true, of course I'm extremely happy and we're ecstatic," Yettaw's wife, Betty, told The Associated Press on Saturday, referring to reports her husband would be freed.

Webb said he also requested that Suu Kyi be released during a meeting with Than Shwe on Saturday. It was the first time the reclusive general has met with a senior U.S. official.

"It is my hope that we can take advantage of these gestures as a way to begin laying the foundations of goodwill and confidence building in the future," Webb was quoted as saying in a statement issued by his office.

Washington has been a leader in isolating the military regime, imposing strong political and economic sanctions because of its poor human rights record and failure to turn over power to Suu Kyi's National League for Democracy party after it won a landslide victory in 1990 elections.

U.S. Secretary of State Hillary Rodham Clinton, on a trip through Asia in February, addressed the administration's dilemma with Burma, also called Myanmar. She said neither tough U.S. sanctions nor engagement by neighbors had persuaded the junta to embrace democracy or release Suu Kyi.

Some of the junta's critics have expressed disappointment with the latest developments.

"I don't think Sen. Webb can be proud for the release of Mr. John Yettaw, while our leader Daw Aung San Suu Kyi, who is the real victim of this conspiracy and injustices, and two women colleagues, are still under detention," said Aung Din of the U.S. Campaign for Burma, a Washington-based group. Daw is a term of respect used for older women.

"This will surely make a negative impression among the people of Burma. They will think that Americans are easy to satisfy with the dictators when they get their citizens back," he said.