BANGKOK, June 19 (Reuters) - Thailand on Monday hosts talks aimed at re-engaging Myanmar's shunned military leaders though important Southeast Asian neighbours are staying away from a gathering critics view as undermining regional unity on the strife-torn country's crisis.

Myanmar's generals have been barred from high-level meetings of the 10-member Association of Southeast Nations (ASEAN) since they seized power in a 2021 coup and unleashed violence on those who challenged their takeover.

The outgoing Thai military-backed government has invited ASEAN foreign ministers, including the one appointed by Myanmar's junta, to discuss a proposal for the regional bloc to "fully re-engage Myanmar at the leaders' level", according to an invitation seen by Reuters and verified by sources.

Thailand's foreign minister, Don Pramudwinai, who called the meeting, told broadcaster Thai PBS an interview aired on Monday that Myanmar's crisis was sending refugees across their common border and had hit trade hard.

"Thailand is the most affected if we let this prolong," Don said. "We can say that Thailand is the only country in ASEAN that wants to see the problems end as soon as possible, which will be beneficial to us."

Myanmar's junta-appointed foreign minister, Than Swe, is due to join the talks, two sources with knowledge of the meeting told Reuters.

But some ASEAN members have declined to attend and others are only sending junior officials.

Indonesia, which as the current ASEAN chair has for months been trying to engage key stakeholders in Myanmar’s conflict in an effort to kick-start a peace process, has declined to join the talks. Indonesian Foreign Minister Retno Marsudi said the latest meeting of the bloc had "arrived at no consensus to re-engage or develop new approaches to the Myanmar issue", according to a letter seen by Reuters and verified by a source.