Permanent secretary Sarun Charoensuwan will represent Thailand at the Asean Summit, the Ministry of Foreign Affairs says.

The summit will consider the risks of AI, including frontier systems, and discuss how they can be mitigated through internationally coordinated action, the British government says.

The Shangri-La Dialogue, which attracts senior military officers, diplomats, weapons makers and security analysts from around the globe, is taking place June 2-4 in Singapore.

The summit in Saudi Arabia comes at a time when the world's biggest oil exporter is flexing its diplomatic muscle across the Middle East and beyond.

Mexican President Andres Manuel Lopez Obrador will host his US counterpart Joe Biden and Canada's Prime Minister Justin Trudeau for talks in Mexico City, the first summit between the three since late 2021.

The summits have been attended by global leaders, and the talks have often been disrupted by friction spilling over from the war in Ukraine as well as flashpoints such as the Taiwan strait and the Korean peninsula.

About 350 protesters had gathered and clashed with police, about 10km from the venue where leaders of the Asia-Pacific Economic Cooperation group are meeting.

Even as Australian business groups and unions assemble at the national capital for the summit, Sydney, is facing a protracted strike by train employees and protests by nurses seeking higher wages.

The US has convened some 30 countries – with the notable exception of Russia – to boost cooperation in fighting the costly and disruptive attacks that have boomed around the world.