Myanmar has been in turmoil since February 2021, when its military ousted an elected civilian government, sparking protests that have turned into an armed rebellion against the ruling junta.
"ASEAN must play an important role in bringing peace back to Myanmar as soon as possible," Paetongtarn told an event in Bangkok.
Thailand will work with Malaysia, next year's ASEAN chair, to use diplomatic means to resolve the conflict, she said, offering her country to act as a mediator to enable talks.
A peace effort by 10-member Association of Southeast Asian Nations (ASEAN)- known as the Five Point Consensus - has made scant progress since its unveiling in April 2021, despite repeated calls for dialogue.
So far, the junta has refused to engage in talks with its rivals, calling them terrorists bent on destroying the country.
The grinding conflict, which has left a third of Myanmar's 55 million people in need humanitarian aid, will be high on the agenda at the Laos gathering.
ASEAN continues to bar the junta leadership from its summits over their failure to comply with the peace plan they had initially agreed to, which has vexed the bloc's most prominent countries.
Last week, ahead of the summit, Indonesia hosted an international meeting involving the United Nations and opponents of Myanmar's military.
