Thailand's military said it is ready to launch a "high-level operation" to counter any violation of its sovereignty, in the strongest words yet in a simmering border dispute with Cambodia that re-erupted with a deadly clash last week.

Claims over ownership of historical sites have raised nationalist tension between the two countries, notably in 2003 when rioters torched the Thai embassy and Thai businesses in Phnom Penh over an alleged remark by a Thai celebrity questioning jurisdiction over Cambodia's World Heritage-listed Angkor Wat temple.

Thailand’s armed forces are ready to defend the border in the face of a deadly clash with Cambodia that erupted last week, a top official said, adding that the country wants to maintain peace with its neighbor.