Thailand and Cambodia continue to fight despite President Donald Trump assuring that they had agreed to end hostilities.

Thailand launched air strikes against Cambodia on Monday as a new wave of fighting erupted between the southeast Asian neighbors, marking the potential collapse of a peace plan presided over by US President Donald Trump just two months ago.

Trump announced the agreement to restart the ceasefire in a social media posting on Friday following calls with Thai Prime Minister Anutin Charnvirakul and Cambodian Prime Minister Hun Manet.

Thailand's military said it was considering blocking fuel exports to Cambodia, as fighting between the two countries spread to coastal areas of a disputed border region two days after US President Donald Trump said the sides had agreed to a new ceasefire.

The escalation broke the ceasefire brokered in July by Trump who threatened to halt trade talks with the two countries unless they ended the fight.