PHNOM PENH: A special Southeast Asian envoy to the crisis in Myanmar on Thursday said he was seeking to visit the country next month and appealed to its military junta to give its blessing for him to talk with a shadow government it has labelled "terrorists".

Prak Sokhonn, Cambodia's foreign minister and new envoy for the Association of Southeast Asian Nations (ASEAN), said engaging the National Unity Government (NUG), a group of members of the ousted administration and other military opponents, was complicated because of the junta's objections.

"You cannot on one hand try to engage with someone and on the other hand, engage with the one who is considered by the former as terrorists," he told a news conference after a meeting of ASEAN foreign ministers.

"We are trying to find a way, of course ... If Naypyitaw is not speaking with the NUG so let the special envoy as the bridge, as the facilitator, speak," he said, referring to Myanmar's capital.

ASEAN last year unexpectedly blocked Myanmar's military government from joining key meetings over a failure to honour a peace plan agreed with the 10-member bloc, which included an immediate end to hostilities and letting a special envoy facilitate dialogue.

Prak Sokhonn said his predecessor as ASEAN envoy was unable to visit Myanmar because of preconditions by some ASEAN members that the ruling generals found unacceptable.

Those included access to Aung San Suu Kyi, the leader of the elected government ousted in last year's coup. Suu Kyi is on trial accused of multiple crimes.

As 2022 chair of ASEAN, Cambodia has caused some concern among fellow members over Prime Minister Hun Sen's preference to directly engage with the generals, including visiting junta leader Min Aung Hlaing last month.

Hun Sen on Wednesday said that without a breakthrough, peace in Myanmar may not be achieved in years.

Prak Sokhonn defended that approach and said this time, ASEAN states had no preconditions for him to visit.

"The reason why the prime minister has taken the approach is because the work of the special envoy was stuck last year," he said.

"Some our colleagues demand a bit too much. I say that they have demanded some hard preconditions that was not acceptable by Naypyitaw."

He said Cambodia would keep engaging the junta to "keep trust and confidence alive for the time being".

Indonesian Foreign Minister Retno Marsudi said it was crucial the ASEAN envoy met all parties in the Myanmar conflict.

"It's important for Myanmar, to listen to concerns and views of those stakeholders," she told a virtual briefing.

Malaysia's Foreign Minister, Saifuddin Abdullah, on Thursday urged Prak Sokhonn to meet with NUG.

Zin Mar Aung, the NUG's foreign minister, on Twitter thanked Saifuddin for his "strong support to find a solution on Myanmar and his clear message to the special envoy".