Prime Minister Hun Sen on Monday said there was no disputed land near Preah Vihear temple, contrary to Thai statements.
The temple is at the center of a longstanding military standoff and saw a number of Thai protesters amassed last week.
Though leaders have sought to solve the border dispute bilaterally, Hun Sen said he would raise the issue with Asean at a summit in October if Thai leaders continued to make public statements about the temple and nearby border.
On Thursday, Thai Deputy Prime Minister Suthep Thaugsuban said roads leading to the temple from the Thai side had been made by the previous government, claiming, "even if there are roads in the border area, it does not mean that the land belongs to Cambodia."
On Sept. 20, around 5,000 Thai demonstrators gathered on the Thai side of the border, near the temple, as leaders of the protest claimed Cambodian civilians and soldiers had settled in disputed areas near the temple.
"I would like to request that Thai leaders stop using Preah Vihear temple in their internal political conflict," he said.
Claims by the Thai prime minister and others about 4.6 kilometers of land near the temple "are not acceptable," he said. Thailand was making unilateral claims using a unilateral map, he said. "Cambodia does not recognize the overlapping or disputed area."
Cambodia uses a map from French surveys in 1904 and 1909 and argues that a 1962 decision at the International Court of the Hague and other documents provide a claim to land near the temple.
"If the Thai prime minister brings a unilateral map to me, I will tear it up in front of [him]," Hun Sen said Monday. "If Thailand militarily invades Cambodia, we will complain to the United Nations Security Council."
Preah Vihear temple was put on a Unesco World Heritage protection list, under Cambodian ownership, in July 2008, sparking demonstrations in Bangkok and an immediate military build-up. Ensuing skirmishes along the border have killed at least seven soldiers.