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

President Donald Trump said Saturday that Cambodia’s prime minister and the acting prime minister of Thailand had agreed to meet immediately

As fighting spread to at least six areas along the arcane frontier, Thailand’s military closed crossings between the countries. The fighting spurred at least 40,000 civilians from more than 80 villages near the border to flee to makeshift bomb shelters of sandbags and car tires.

Thai and Cambodian troops clashed in at least six areas along the countries’ shared 510-mile border on Thursday, killing one Thai soldier and nearly a dozen Thai civilians. The fighting—the second instance of armed confrontation between the two countries in almost two months—has sparked fears that the conflict could escalate into open warfare.

US President Donald Trump on Saturday announced that both the leaders from Thailand and Cambodia have agreed to meet immediately for ceasefire talks after three days of clashes

The countries continued to trade fire on Friday, and at least 16 people are reported to have been killed.

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.