via Phnom Penh Post, 24 September 2018:

The Cambodian government is preparing a proposal to register the ancient Koh Ker temple in Preah Vihear province as a Unesco World Heritage Site.
Minister of Culture and Fine Arts Phoeurng Sackona made the announcement last week at a meeting in Siem Reap province, of the International Coordinating Committee for Safeguarding and Development of the Historic Site of Preah Vihear.
The Koh Ker site constitutes “one of the marvels of Cambodian monumental heritage,” according to Unesco. Sackona said efforts to register Koh Ker might be aided by the inclusion of Sambor Prei Kuk archaeological complex, which was listed as a World Heritage Site last year.
Source: Preah Vihear’s ancient Koh Ker temple seeks World Heritage Status, National, Phnom Penh Post