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.

The talks, announced by a spokesperson for the Thai prime minister's office on Sunday, come after pressure from U.S. President Trump to reach a ceasefire.

"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".