The United States is asking Asean member states to review their diplomatic relationships with North Korea and fully implement United Nations sanctions to help isolate the Pyongyang regime.
At a lunch that he hosted for visiting foreign ministers of the ten- member grouping, US Secretary of State Rex Tillerson underscored his nation's commitment to Asean, but also sought its help to cut funding streams for North Korea's nuclear and missile programmes.
All Asean members have diplomatic relations with North Korea and five have embassies there. Diplomats later confirmed that the issue of tensions on the Korean peninsula dominated the 45-minute meeting.
Asean ministers at the meeting, including Singapore's Foreign Minister Vivian Balakrishnan, expressed "grave concern" over the escalation of tensions on the Korean peninsula in a statement, later adding: "We strongly urge the DPRK (North Korea) to fully comply with its obligations (under) United Nations Security Council resolutions."
Mr Patrick Murphy, US State Department's Deputy Assistant Secretary for South-east Asia, who was at the meeting, later told reporters: "We really want to double down and bring the UN Security Council resolutions into full force."
The US wants countries to make efforts to "deny the revenue streams that North Korea has enjoyed around the region, and to take a look at diplomatic relations, to minimise them so that North Korea does not gain benefit from its diplomatic channels for its nuclear and missile aspirations", he said.
"I think, on this issue, a considerable common ground was identified," he added. "The region is increasingly unified on this issue."
In an interview with National Public Radio yesterday, Dr Balakrishnan said: "We've repeatedly urged North Korea to fully comply with UN Security Council resolutions. On our part and on the part of all South-east Asian nations, we intend to fully comply."
Singapore had no diplomatic mission in Pyongyang, so relations were already minimal - and the authorities would not tolerate North Korea using the country for illicit financial transactions, he said.
The meeting also served to emphasise that the US and Asean remain close partners.
The US is committed to upholding freedom of navigation in the South China Sea, Mr Tillerson said.
The meeting came on the heels of a trip to Jakarta by US Vice-President Mike Pence during which he visited the Asean secretariat, and confirmed that President Donald Trump would attend the East Asia and US-Asean summits in the Philippines in November.
Mr Danny Russel, a former top State Department official for East Asia and the Pacific who is now diplomat in residence and senior fellow at the Asia Society, said the Trump administration recognised Asean was a valuable partner and "we have a huge interest in promoting Asean unity and connectivity".
The biggest takeaway from the meeting was that at a very early stage of the new administration, there had been a substantive face- to-face engagement with Asean, Mr Russel told The Straits Times.
"It is a powerful affirmation that South-east Asia matters to the US, and the US matters to South-east Asia," he said.