International negotiators have failed to reach an agreement on whether Iran should be invited to Syria peace talks in Geneva next month.

The United Nations' joint special representative for Syria told a news briefing that the US were refusing to let Iran participate.

Speaking in Geneva, Lakhdar Brahimi made it clear that he would continue to work with Iranian officials even if they were not officially invited.

Washington were "not convinced" that inviting Iran to participate was "the right thing to do", Mr Brahimi said.

He went on to list the nations that are going to send delegates to participate in the talks.