Thailand’s caretaker government is proposing to “fully re-engage” Myanmar’s military rulers and has asked ASEAN foreign ministers to an informal meeting on Sunday in a bid to jump-start a stalled peace plan, according to a letter obtained by Reuters on Friday and individuals familiar with the invitation.

The proposal was made in a June 14 letter to ASEAN counterparts from Thailand’s Foreign Minister Don Pramudwinai, which was seen by Reuters and confirmed by three sources with knowledge of the planned meeting.

Indonesia, the current chair of the Association of Southeast Asian Nations (ASEAN), has declined to attend the meeting, according to three diplomatic sources. Indonesia has been seeking to advance a peace process agreed two years ago with the junta and ASEAN, which has barred the generals from its high level meetings.