The Asean Defence Ministers Meeting Plus in Bangkok will feature the defence chiefs from the 10-nation bloc and eight global partners, including US Secretary of Defence Mark Esper and his Chinese counterpart Wei Fenghe.
Beijing insists the entire South China Sea up to the coasts of the Philippines, Malaysia and Taiwan belongs to China – a claim rejected by an international court of arbitration in 2016.
This has led to a prolongued display of sabre-rattling between the US and China who remain at loggerheads over the disputed waters and Beijing’s efforts to militarise key strategic areas.
Washington sent another warning signal to Beijing earlier this week when a warship was deployed through the disputed Taiwan Strait.
The USS Chancellorsville sailed through the disputed waters on what the US military has called a “routine” operation.
Commander Reann Mommsen said the guided-missile cruiser travelled through the Strait to demonstrate “commitment to a free and open Indo-Pacific”.
It was the ninth-time a US vessel has sailed through the waters this year.
The Taiwan Military confirmed it has “full grasp” of the US operation and “no abnormalities” took place during its voyage.
In a statement the military said it had “full grasp during the entire process of the neighbouring seas, the air and naval spaces, and other relevant developments, with no abnormalities during the period”.
The US warship USS Antietam was the last to sail through the waters last September.
Tensions between Taiwan and China have soared in recent day in the lead-up to the election in Taiwan.
China has stepped up a campaign to “reunify” with what it considers a wayward province.
Taiwan Foreign Minister Joseph Wu warned China could attack the democratic and self-ruled island if any threat to China’s ruling Communist Party – amid growing economic pressure from the ongoing trade war with the US.
Ma Xiaoguang, spokesman for China’s Taiwan Affairs Office said Mr Wu’s comments were “complete nonsense and absolute rubbish”.
Mr Xiaoguang said: “Recently, in order to seek benefit for the elections, they have been weaving various lies to intimidate, threaten and mislead the people of Taiwan.
“I think compatriots on both sides of the Taiwan Strait must be highly vigilant and not easily misled.”