Thailand and Cambodia clashed for a fourth day on Sunday, despite US President Donald Trump warning them they are risking potential trade deals with the US. The US president said on Saturday the leaders of the two countries had agreed to meet to negotiate a ceasefire.

"The U.S. already flunked the test and that should be a wakeup call," a former senior U.S. State Department official told Newsweek.

The latest flare-up started on Thursday, with intense fighting spreading across multiple border areas. Early Saturday, Thailand’s navy joined the army in repelling what it described as incursions by Cambodian troops at three points in eastern Trat province.

China has blamed “Western colonialists” for ongoing clashes on the Thai-Cambodian border that have left at least 15 people dead and forced tens of thousands to flee their homes.

Thailand favours bilateral negotiation rather than third-party mediation to resolve its military conflict with Cambodia, two Thai officials said, as fighting along their disputed border continued unabated.

Tensions have bubbled between the two neighbors for months, flaring on Thursday as Cambodia and Thailand exchanged fire.

Thailand bombed Cambodia with F-16 fighter jets on Thursday, as relations between the two countries imploded following clashes on a disputed border near the Emerald Triangle.

Four dead as Tropical Storm Wipha tears through Thailand, China and into Vietnam - Heavy rain in China's eastern province of Shandong kills two people and leaves 10 missing