Foreign Affairs Minister Prak Sokhonn has blamed Laos for bogging down demarcation work along the border.
Both nations began work to demarcate the 540-kilometre border in 2000. So far, the government has demarcated 84 percent of the border with Laos.
Mr Sokhonn said the remaining 16 percent could have been done had the Lao government not requested for an old French map to be referenced in December.
“We cannot accept the Lao request because they want to use a map produced in 1902, a year when France had not yet transferred Stung Treng province to Cambodian territory,” he said. “This work has been a headache.”
“In 1998, the two countries agreed on which maps to use,” he added. “So why are they now asking for a review of what was already agreed upon? This could mean that the maps we used to demarcate 86 percent of the border will become invalid.”
Mr Sokhonn stressed that the government will not concede any land to Laos.
“If our friend does not accept this, we have no choice but to go to the International Court [of Justice] because we cannot provide concessions,” he said.
In August 2017, hundreds of Lao soldiers invaded Ou’ Alai and Ou’Ta Ngav areas in Stung Treng province’s Siem Pang district during a dispute about the construction of a road near the border.
Prime Minister Hun Sen then ordered thousands of troops to be deployed along the border and issued an ultimatum to Laos to pull out its forces within six days.
A day later, Laos agreed to withdraw its troops after Mr Hun Sen flew to Vientiane to talk with Lao Prime Minister Thongloun Sisoulith.
Meanwhile, Cambodia and Laos have agreed to look into the possibility of opening additional border checkpoints to facilitate trade and the movement of people between the two countries.
Interior Minister Sar Kheng yesterday presided over a bilateral meeting with Vilay Lakhamfong, Minister of Lao Security, and both signed a series of agreements, ministry spokesman Phat Sophanith said.
Speaking to reporters after the meeting, Mr Sophanith said the opening of new border checkpoints is crucial to promote the exchange of people, noting that the two countries share only one border checkpoint so far.
“We agreed to look into feasible ways of having more legal checkpoints to encourage bilateral trade and convenient travelling for people,” he said.
Mr Sophanith said the government will consider opening more border checkpoints in Strung Treng province or Ratankkiri province.
Mr Sophanith added that during the meeting both parties also highly valued cooperation on security in 2018, and pledged to ensure safety and social order along the border in 2019.
“The two parties will continue to exchange information and close cooperation along the border,” he said. “We also pledged to prevent and crack down on drug trafficking.”