US President Barack Obama has arrived in Shanghai in China where he will hold talks with President Hu Jintao.
They are expected to discuss the issue of economic ties between their two countries.
Earlier, Mr Obama called for the release of Burma opposition leader Aung San Suu Kyi.
He made the call when he took part in a meeting with the prime minister of Burma, which is also known as Myanmar, and other southeast Asian leaders in Singapore this morning.
However, Mr Obama did not speak or shake hands with Thein Sein at the meeting with the ten leaders of the Association of Southeast Asian Nations (ASEAN).
White House spokesman Robert Gibbs said President Obama reiterated his call for Ms Suu Kyi to be freed.
Mr Gibbs said: 'He brought that up directly with that government.'
Ms Suu Kyi has been detained for 14 of the past 20 years and remains under house arrest.
However, she has been allowed to meet US diplomats and last week expressed hope that those contacts would lead to democratic reforms.
The meeting in Singapore marked the first time in history a US leader had met with his counterparts in the 42-year-old group, which founded during the Vietnam War.
