Thailand is warning Cambodia against discussing its management plan for the Preah Vihear temple until after the International Court of Justice ruling on the temple this year.
Cambodia is hosting the 37th World Heritage Committee (WHC) meeting from June 16-27.
Permanent secretary for natural resources and the environment Chote Trachoo said the Thai delegation could walk out of the meeting room if the issue is raised.
The Thai committee, chaired by Natural Resources and Environment Minister Preecha Rengsomboonsuk, yesterday called a meeting to outline the Thai stance on the issue.
"We held this meeting to send this message to Cambodia," Mr Chote said.
The delegation had previously walked out of the session in 2011, when former natural resources and environment minister Suwit Khunkitti led the Thai team at the 35th WHC meeting in Paris.
Mr Chote said the committee's view is the matter should be discussed after the ICJ ruling on the disputed territory surrounding the temple.
Cambodia has requested the ICJ interpret its 1962 judgement, which gave Phnom Penh sovereign rights over the Preah Vihear temple but did not mention a 4.6 square kilometre area which has been claimed by both countries since then.
The ICJ has called oral hearings for April 15-19 in The Hague, Netherlands. The ruling is expected in October or November.
Mr Chote said the Thai delegation would use all the means it could to object to the Preah Vihear management plan if Phnom Penh insists on discussing it.
The delegation had walked out of the WHC meeting in 2011 because Mr Suwit was unhappy that Cambodia's proposed management plan for the Preah Vihear temple was on the agenda.
Mr Suwit had also announced Thailand would withdraw from Unesco's World Heritage Convention.
However, the subsequent Pheu Thai-led government eventually decided to reinstate Thailand to the convention.