Donald Trump’s Secretary of State told a virtual meeting of foreign ministers not to “let the Chinese Communist Party walk over us”. ASEAN, also known as the Association of Southeast Asian Nations, is made up of ten countries including Vietnam and Thailand.
It has the aim of promoting economic and security co-operation between its member states.
This ministerial meeting between ASEAN member states took place amid military tensions between the US and China, both of which have issued sharp rhetoric over the South China Sea.
Both nations have also been moving military assets into the region’s disputed territory, Al Jazeera reports.
Mr Pompeo also insisted ASEAN member states “don’t just speak up but act.”
The Chinese embassy in the US said: “The United States is not a country directly involved in the disputes. However, it has kept interfering in the issue.”
The US has had a strategic partnership with ASEAN for five years, which the US Department of State says is “built on our shared principles”.
The department added Mr Pompeo had discussed “pressing international issues” as well as health programmes.
It said in a statement: “The Secretary and ASEAN Foreign Ministers shared their common position that all disputes in the South China Sea should be resolved peacefully and in line with international law, namely the UN Convention on the Law of the Sea.”
The group’s ministerial meeting was this year held in Vietnam, though members were represented virtually due to social distancing.
As well as military tensions in the South China Sea, countries discussed the economic consequences of the COVID-19 pandemic.
The Asia Foundation representative Thomas Parks told Al Jazeera: “I think that this is foremost in the minds of the foreign ministers, and I think they’ll be looking for creative and practical ways of trying to quickly recover in 2021.”
He said ways of allowing tourism to continue between countries may be one such measure.