The American jailed for visiting Myanmar's detained pro-democracy leader, Aung San Suu Kyi, is in a Bangkok hospital after being released and deported.
John Yettaw, whose health is described as fragile, left Myanmar, also known as Burma, on a plane with the United States senator Jim Webb, who negotiated his release on Saturday.
A court in Myanmar court sentenced Ms Suu Kyi to another 18 months of house arrest for violating a security law after Mr Yettaw swam uninvited to her lakeside home in May.
Mr Yettaw was sentenced to prison in a parallel trial on three charges, including immigration offences.
Mr Webb held talks on Saturday with Myanmar's military leader, Than Shwe - the first US official to do so.
Mr Webb says he asked Myanmar to free Ms Suu Kyi - whom he met while on his visit to the country - and let her take part in politics.
The plea came during talks that secured the release of American John Yettaw, who had been jailed for visiting Ms Suu Kyi.
His uninvited visit also to led to Ms Suu Kyi's extended detention under house arrest.
The director of the Burma Campaign UK, Anna Roberts, says the US appears to be softening its stance on the military.