Cambodia’s most influential politician called for a leadership change in Thailand, citing doubts about the prime minister’s ability to manage a border dispute between the two countries.

Thailand's prime minister and Cambodia's influential former premier are visiting different parts of their disputed land border on Thursday as tensions simmer between the two neighbours over a territorial dispute and the Thai government teeters on the brink of collapse.

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.