KUALA LUMPUR (REUTERS) - South-east Asian countries on Monday (Oct 4) voiced disappointment about army-ruled Myanmar's commitment to an agreed peace plan, with one foreign minister saying he was concerned about the junta leader attending a regional summit later this month.

Myanmar's military has been condemned by much of the international community for its Feb 1 coup and bloody crackdown on strikes and pro-democracy demonstrations, which derailed a decade of tentative democracy and economic reform.

World powers, including the United States, China and the United Nations, had backed diplomatic efforts by a special envoy of the Association of South-east Asian Nations (Asean) to engage the junta and its opponents and end the crisis.

"There's been no significant progress in Myanmar. The military has not given a positive response to what has been attempted by the special envoy," Indonesian foreign minister Retno Marsudi told a news conference following a meeting of regional counterparts.

"Most members expressed disappointment," she said. "Some countries expressed that Asean cannot act business as usual... when looking into this development."

Singapore Foreign Minister Vivian Balakrishnan said the envoy had briefed Asean on the challenges he had faced in Myanmar.

He said ministers urged the State Administrative Council (SAC), as the junta is known, to cooperate.

Malaysian Foreign Minister Saifuddin Abdullah in a tweet went a step further and said that unless there was progress "it would be difficult to have the chairman of the SAC at the Asean summit".

It was not clear whether a proposal had been made to exclude Myanmar's junta leader Min Aung Hlaing from the summit later this month, which would be highly significant in Asean, which has traditionally preferred an engagement approach.

Myanmar's long history of military dictatorship and alleged human rights abuses has been Asean's most tricky issue, testing the limits of its unity and its policy of non-interference.

Myanmar military spokesman Zaw Min Tun did not answer calls from Reuters on Monday.

At a news conference last week, he said Myanmar was cooperating with Asean "without compromising the country's sovereignty".