Participants at the Copenhagen global climate summit opened talks Monday at the start of the holiday season, but they won't be surrounded by festive Christmas decor, according to Denmark's Foreign Ministry.

Since Christmas is a religious holiday, it has no place at a United Nations event, said officials planning the event.

A sponsor providing fir trees for the conference's Christmas trees learned this the hard way when it was turned away by planners of the international event, the Copenhagen Post reported.

The trees, commonly used as Christmas trees in Denmark, were originally to be placed outside the Bella Center, where the 11-day conference will be held from Dec. 7 — Dec. 18.

Denmark's prime minister said 110 heads of state and government will attend the final days of the two-week conference. President Barack Obama's decision to attend the end of the conference, not the middle, was taken as a signal that an agreement was getting closer.

"We have to remember that this is a U.N. conference and, as the center then becomes U.N. territory, there can be no Christmas trees in the decor, because the U.N. wishes to maintain neutrality," said Denmark Foreign Ministry official Svend Olling.

Fir trees otherwise reach the climate-friendly standards of the conference planners. Firs bind carbon dioxide and prevent its release into the atmosphere.

Click here for more from the Copenhagen Post.