UNITED NATIONS — Cambodia is calling for an emergency U.N. Security Council meeting to prevent a war with Thailand over an ancient temple in a disputed border area.

The tensions between the two countries, which reached a boiling point yesterday, have been mounting since July 7, when the United Nations designated the Preah Vihear temple as a World Heritage Site.

With 4,000 Thai and Cambodian troops massed along the shared border near the temple, the Cambodian ambassador to the United Nations, Sea Kosal, said in a letter to the president of the Security Council that although his country offered “maximum” concessions during a recent high-level meeting with Thai officials, bilateral talks have failed.

Mr. Kosal called on the council to convene an “urgent” meeting “to prevent an escalating situation leading to imminent armed conflicts.”

Thai officials have urged bilateral negotiations on the border dispute, as have fellow members of a regional group, the Association of Southeast Asian Nations, which has sought to persuade Cambodia not to refer the dispute to the Security Council.

ASEAN members have struggled to deflect recent American attempts to raise the issue of Burma at the council, and they now are said to be concerned about possible council intervention in another regional flash point.

“The military standoff between the two countries has embarrassed their neighbors, who take pride that their organization” can resolve regional problems, an editorial yesterday in an Indonesian English-language newspaper, the Jakarta Times, said.

The current dispute arose out of a Cambodian request that the U.N. Educational, Scientific, and Cultural Organization declare the Preah Vihear temple and the surrounding area a World Heritage Site. The Thai government at first supported the designation, but switched course after protesters said the move would undermine Thailand’s claim to the area around the temple.