The declaration from Trump comes after he said over the weekend that he had spoken to the leaders of Cambodia and Thailand, urging a ceasefire, adding the U.S. would not get back to the "trading table" with the southeast Asian countries until fighting stops.

BANGKOK/PHNOM PENH,July 28 (Reuters) - A ceasefire between Cambodia and Thailand came into effect at midnight (1700 GMT) on Monday, hours after they agreed to halt their deadliest conflict in more than a decade following five days of intense fighting that displaced over 300,000 people.