Cambodia's powerful former leader Hun Sen and Thailand’s prime minister, Paetongtarn Shinawatra, on Thursday made separate visits to border areas as the two countries remain locked in an ongoing dispute that has resulted in strict land crossing restrictions and several economic boycotts.

The Thai military closed its border to nearly all travelers to Cambodia as diplomatic tensions rise over a territory dispute between the two neighboring south Asian nations.

The reescalation of conflict was sparked on May 28, when a Cambodian soldier was killed in an early morning clash between both nations’ troops, in an area called the Emerald Triangle—the shared border between Thailand, Cambodia, and Laos. The area remains disputed as both Thailand and Cambodia lay claims to parts of the region.