The long-running border dispute between the two countries reportedly escalated into intense fighting with artillery and ground troops on Thursday. The crisis was discussed by the UN Security Council on Friday.

"Cambodia requested an immediate ceasefire, without conditions, and we also call for a peaceful resolution of the dispute," Cambodian Ambassador to the UN Chea Keo said after a closed-door meeting of the UN Security Council attended by Cambodia and Thailand.

The Security Council called on both sides to exercise maximum restraint and find a diplomatic solution, and we call for that as well, Keo pointed out.

Relations between the Southeast Asian neighbors have deteriorated sharply since May, when a Cambodian soldier was killed in an armed clash in one of several small territories that both countries claim as their own.

Thailand has evacuated more than 138,000 people from border regions in recent days and reported 15 casualties in border clashes, saying 14 civilians and one soldier were killed.