PHNOM PENH -- Cambodian Prime Minister Hun Sen on Friday accused neighbouring Laos of sending troops into Cambodian territory in April and set an Aug 17 deadline for their departure, warning that he was mobilising soldiers to the border area.
Cambodia and Communist Laos are key allies of giant northern neighbour China, backing its "One Belt, One Road" drive to build regional infrastructure, but it was not immediately clear how their dispute would affect the plans.
Hun Sen said at a ceremony in the Cambodian capital he had been in touch with the government in Laos about 30 soldiers from Laos who had crossed into the area, where some remained during daytime.
"I can no longer keep patience," Hun Sen added. "It's not right that we fight each other, but if they don't withdraw, we must do it ... We don't declare war, we just ask to get our own land back."
Laos and Cambodia have a territorial and border demarcation dispute, an official at the Laos embassy in Phnom Penh told Reuters.
"We have not yet agreed the border line with each other," said the official, who declined to be identified. "A border commission has not come to check it."
Cambodia should stop clearing the area for road-building activities, in order to allow checks by inspection panels from both countries, he said.
China could help resolve the dispute, said an official from a Cambodian think-tank, adding that he feared it might provoke clashes.
"China has influence on the two countries, and if they want to solve it, only China can help solve it," said Ou Virak of the Future Forum think-tank.
"This issue might lead to clashes, like when it happened with Thailand," he told Reuters.
In a long-running dispute, land around an ancient temple on the Thai-Cambodian border was the scene of sporadic gun and artillery battles, with 28 killed in the worst incident in 2011.
In November 2013, a UN court in the Hague ruled that part of the land around the Preah Vihear Temple belonged to Cambodia and ordered Thailand to withdraw its forces from the area.
Last month, Thailand approved construction of the first phase of a $5.5-billion railway to link its industrial eastern seaboard with southern China through landlocked Laos.
In another land dispute, Cambodia accuses neighbouring Vietnam of encroaching on its territory. The two sides met last year in Phnom Penh but the dispute remains unresolved.