Southeast Asian nations like the Philippines and Malaysia rely heavily on oil from the Middle East, much of it exported through the key strait that's been effectively closed during the conflict.

Foreign ministers of the 11-member Association of Southeast Asian Nations met online to discuss the US-Israeli war against Iran, hours before the US Navy was to start a blockade of Iranian ports.

US President Donald Trump ordered the blockade of the key chokepoint for seaborne oil trade after negotiations between the warring sides in Pakistan collapsed over what the American leader said was the Islamic republic's refusal to abandon its ambition to develop its own nuclear weapons.

ASEAN foreign ministers agreed to urge the United States and Iran to "continue negotiations that will lead to the permanent end of the conflict and lasting peace and stability in the region", said a joint statement issued after the meeting.

They also called for the "full and effective implementation" of an ongoing two-week ceasefire and the "restoration of the safe, unimpeded, and continuous transit passage of vessels and aircraft in the Strait of Hormuz".

Around 20 percent of the world's seaborne oil trade passes through the Strait of Hormuz, according to the International Energy Agency, 80 percent of it bound for Asian markets.

The Philippines, which holds ASEAN's rotating chairmanship, last month adopted a four-day work week for civil servants in a bid to conserve fuel, while Malaysia, Thailand and Vietnam encouraged public employees to work from home.