Armed clashes on the remote, disputed border between Cambodia and Thailand killed at least 12 people on Thursday, in a dramatic escalation of tensions that threatens to erupt into a broader conflict.

Cambodia is seeking to "internationalise the issue to serve its own political objectives", Thailand’s ambassador to the United Nations Cherdchai Chaivaivid told a closed-door UN Security Council meeting.

Thailand and Cambodia have agreed to a ceasefire following days of border clashes which claimed dozens of lives and displaced nearly 300,000 people.