AMMAN (Reuters) - A four way meeting between senior officials from the United States, Russia, the United Nations and the Syrian opposition is scheduled in Munich on Saturday to discuss a political transition in the country, Syrian opposition sources said.

Syrian National Coalition President Moaz Alkhatib will meet U.S. Vice President Joe Biden, Russian Foreign Minister Sergei Lavrov, United Nations envoy Lakhdar Brahimi, Syrian Coalition officials said on Friday.

The meeting, on the sidelines of the Conference of Security and Cooperation in Europe, comes after Alkhatib survived a challenge to his authority after saying he would be willing to talk with Syrian officials without Assad stepping down first.

(Reporting by Khaled Yacoub Oweis, Amman newsroom; Editing by Jon Boyle)