Fresh cross-border clashes between Thailand and Cambodia broke out on Sunday hours after US President Donald Trump announced the two Southeast Asian nations had agreed to ceasefire talks.

Thailand and Cambodia are set to hold talks Monday to discuss an end to their deadly border clashes after US President Donald Trump warned Washington wouldn’t make a trade deal with either country while the conflict continued.

"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".