US Senator Jim Webb, on a mission to "re-engage" Washington in South-East Asia, met Myanmar's military supremo as well as detained opposition leader Aung San Suu Kyi Saturday, government officials said, according to dpa. Webb also negotiated the release of US national John William Yettaw, 54, who was sentenced Tuesday with Suu Kyi to seven years in prison with hard labour, US media later said. Yettaw had been sentenced for swimming to the house-cum-prison of Suu Kyi on May 3 on a mission to warn her of an assassination attempt he had envisioned. Webb was quoted by US media as expressing thanks to the Myanmar military government for acceding to the request for Yettaw's release. The junta said the uninvited guest had violated the terms of a previous house detention of Suu Kyi, who has spent 14 of the past 20 years under detention. Webb, a Democrat from Virginia who is chairman of the US Senate's East Asia and Pacific Affairs Subcommittee, arrived in Myanmar's military capital, Naypyitaw, Friday when he held talks with Prime Minister Than Sein and government-backed civil organizations. On Saturday, Webb met with junta chief Senior General Than Shwe, making him the first US politician to have a personal chat with the military supremo since he assumed power in 1992. After meeting Than Shwe, Webb flew on to Yangon where he met with Nobel peace prize laureate Suu Kyi at a government guest house, government sources said. Suu Kyi was taken under army guard from her house-cum-prison for the brief meeting. The nature of Webb's talks with Than Shwe and Suu Kyi were not disclosed, but Webb was expected to give a press conference in Yangon Sunday prior to his departure for Bangkok. Webb is a proponent of change in US foreign policy toward Myanmar, a pariah state among Western democracies that has been condemned for its poor human rights record and has been subject to economic sanctions for decades. The senator also met with representatives of Suu Kyi's National League for Democracy opposition party Saturday morning. Webb's trip to Myanmar - part of a five-nation tour of South-East Asia that is also to include stopovers in Thailand, Cambodia and Vietnam - comes days after Than Shwe placed pro-democracy icon Suu Kyi under house arrest for the next 18 months, commuting a court sentence of three years in prison. "It is vitally important that the United States re-engage with South-East Asia at all levels," Webb wrote on his website after a visit to Laos, whose communist leadership sided with the Vietnamese communists against the US military in the 1960s and '70s. Myanmar pro-democracy groups have questioned the timing of Webb's visit and cautioned him not to become a tool of the ruling regime. "We are concerned that the military regime will manipulate and exploit your visit and propagandize that you endorse the trial of Daw Aung San Suu Kyi and the imprisonment of over 2,100 political prisoners," said a joint statement sent to the US embassy in Yangon by the All Burma Monks Alliance, 88 Generation Students and All Burma Federation of Student Unions.