Cambodia and Thailand exchanged fire across their disputed border for a fourth day on Sunday, hours after US President Donald Trump announced the two Southeast Asian nations had agreed to ceasefire talks and threatened continued fighting would jeopardize their trade deals with Washington.

"I made it clear to [Trump] that Cambodia agreed with the proposal for an immediate and unconditional ceasefire between the two armed forces," Cambodian PM Hun Manet said after the phone call, adding that Trump's mediation "will truly help protect the lives of many soldiers and civilians".

Thailand expressed cautious support. Phumtham thanked Trump and said that Thailand agreed in principle to a ceasefire but stressed the need for “sincere intention” from Cambodia, the Thai Foreign Ministry said. Phumtam called for swift bilateral talks to discuss concrete steps toward a peaceful resolution, it said.