By Artorn Pookasook and Chantha Lach SISAKET, Thailand/PHNOM PENH (Reuters) -Cambodia and Thailand each said the other had launched artillery attacks across contested border areas early on Sunday, hours after U.

Thailand and Cambodia's leaders are due to meet for peace talks on Monday, as a festering territorial dispute along their shared frontier dragged into a fifth day of open combat.At least 35 people have been killed and more than 200,

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

U.S. President Donald Trump said on Sunday he believed both Thailand and Cambodia wanted to settle their differences after he told the leaders of both countries that he would not conclude trade deals with them unless they ended their fighting.

At least eight civilians were killed in attacks in a disputed border area between Cambodia and Thailand on Thursday, according to authorities. Thailand said Cambodian soldiers opened fire on a military base in Surin.