State Department Counselor Derek Chollet said during a teleconference in Indonesia that a decision last week by Southeast Asian countries to exclude Myanmar's junta from an upcoming summit was an example of how international pressure can work.

He also said the international community must be realistic about the limited tools it has to bring change in Myanmar, Reuters reported.

Earlier on Wednesday, Chollet, who is in the region to discuss Myanmar ahead of the ASEAN summits, said in a tweet that he had had a "productive" meeting with Monetary Authority of Singapore Deputy Managing Director Ho Hern Shin.

"[We] discussed ways to limit the Burmese military regime's access to overseas financial assets," said Chollet, a senior adviser to Secretary of State Antony Blinken.

Also on Wednesday, a senior US official said that the United States sees the decision by Southeast Asian nations to exclude Myanmar's leader from a regional summit as very significant but more needs to be done to address the challenges the country is facing after the military coup there.

The 10-member Association of Southeast Asian Nations (ASEAN) decided last week to invite a non-political representative from Myanmar to its Oct. 26-28 summits, snubbing military chief Min Aung Hlaing.

"This reflects a very significant step," Edgard Kagan, senior director for East Asia and Oceania at the White House National Security Council, told an event at Washington's Center for Strategic and International Studies think tank.

"Obviously, we believe that this is not enough, and addressing the challenges that are posed by the coup in Myanmar, as well as the extraordinary difficulties that people in Myanmar are facing as a result of the coup [...] require a broader and I think more effective effort."

Kagan did not specify the steps needed. Blocking Min Aung Hlaing was a big step for ASEAN, whose members have longed pursued a policy of staying out of each other's affairs and have discouraged sanctions and other measures to isolate Myanmar.

Kagan said addressing the issues faced in Myanmar, also known as Burma, would require cooperation between ASEAN countries, as well as partners outside.

"It's very clear that this is not a situation that's going to get better on its own," he said, adding that the United States was willing to work with ASEAN on the issue.

"It is clear that there is growing frustration in the region with the situation with the situation in Myanmar, also growing concern. The reality is that the quality of governance in Myanmar has dropped precipitously, that the people of Myanmar are facing extraordinary challenges."

Meanwhile, Malaysia said Thursday that Southeast Asia's regional bloc should do some "soul-searching" on its policy of not interfering in members' internal affairs to deal effectively with issues like the Myanmar crisis.

Saifuddin Abdullah, foreign minister of member state Malaysia, said he understood that the policy is "almost sacrosanct" in ASEAN and had been "useful and practical" in the past.

"But when we are faced with situations like the one that is currently occurring in Myanmar, then perhaps ASEAN should actually do some soul-searching," he said at a virtual dialogue on human rights in Myanmar.

"As much as the issue in Myanmar is local and national [...] it has impact on the region and we should also recognize the concerns of the other nine member states," he said.

The junta leader was excluded after authorities refused to allow an ASEAN special envoy to meet with ousted civilian leader Aung San Suu Kyi.

Myanmar, mostly ruled by the military since a 1962 coup, has been a thorn in ASEAN's side since it joined in 1997.

Elections in 2015 overwhelmingly won by Suu Kyi's National League for Democracy (NLD) party ushered in the start of civilian rule -- but this was cut short by the most recent coup.

The Southeast Asian bloc has been under international pressure to address unrest and the junta's brutal crackdown on dissent.

Diplomatic sources said key ASEAN members like Malaysia, Indonesia, the Philippines and Singapore pushed for tough action to stop the group's credibility being tarnished.