Inviting Iran and other countries that are interested in Syria's conflict to UN-brokered talks in Geneva has not decided yet, said a UN official.

In statements on Thursday, Khawla Matar the chief of staff of UN Special Envoy of the Secretary-General for Syria Staffan de Mistura asserted that it is not clear which countries will take part in the talks.

Staffan de Mistura has said that he will try to invite all interested countries and factions to the talks, Matar added.