On Monday, Ban said Iran is a very important regional power that can play a major role in helping end the Syrian conflict and should be allowed to participate in next month's peace conference in Switzerland.

Lakhdar Brahimi, the UN-Arab League Syria envoy, said Friday the United States is blocking Iran's participation.

The UN chief said he plans to issue invitations before the end of December to the Jan. 22 peace conference and expressed hope that "the question of Iran's participation is resolved soon."

"Negotiations will be difficult, but without them there is only bloodshed and despair on the horizon," Ban added.

Iran has said that Syrians are the ones who should decide on their political destiny.

The conference would bring representatives from Syria's government and elements of the opposition to negotiate an end to the fighting that has raged on since March 2011.

Geneva 1 conference was held in June 2012, where international parties laid out a peace plan for Syria that calls for a transitional governing body.

According to reports, the Western powers and their regional allies -- especially Qatar, Saudi Arabia, and Turkey -- are supporting the militants operating inside the country.

NTJ/SHI