The decision comes at an emergency meeting of the foreign ministers from the Association of Southeast Asian Nations ahead of its three-day summit from October 26.
Myanmar's junta chief will be excluded from an upcoming ASEAN summit, the group has said.
Saturday statement from the group is seen as a rare rebuke as concerns rise over the Myanmar military government's commitment to plans on defusing a bloody crisis.
Foreign ministers from the Association of Southeast Asian Nations agreed at an emergency meeting late on Friday that Min Aung Hlaing will not be invited to the October 26-28 summit, current ASEAN chair Brunei said.
The bloc, widely considered a toothless organisation, took a strong stand after the junta rebuffed requests for a special envoy to meet with all parties concerned - a phrase seen to include ousted civilian leader Ang San Suu Kyi.
The statement noted "insufficient progress" in the implementation of a five-point plan agreed by ASEAN leaders in April to end turmoil following a coup in February.
It said some member states recommended giving "space to Myanmar to restore its internal affairs and return to normalcy".
It was decided "to invite a non-political representative from Myanmar" to the summit, "while noting the reservations from the Myanmar representative", the statement said.