Thailand warned its conflict with neighboring Cambodia could “potentially develop into a war” as troops used rockets and artillery to shell targets along their contested border for a second

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

China urged Cambodia and Thailand to resolve their border dispute through friendly dialogue, offering to play a constructive role by upholding an "objective and fair" position, its foreign ministry said.