GENEVA, Dec 18 (Reuters) – U.N. Special Envoy Staffan de Mistura said on Tuesday after talks with Russia, Iran, and Turkey that “there is an extra mile to go” in the “marathon effort” to ensure a credible, balanced and inclusive constitutional committee for Syria.

De Mistura, addressing a news conference, said that he would report to U.N. Secretary-General Antonio Guterres on Wednesday and to the Security Council on Thursday and expected his successor Geir Pedersen to build on his work from Jan. 7.

“There is still an extra mile to go, but we do certainly appreciate the intensive work that has been done,” he said.

(Reporting by Stephanie Nebehay; Editing by Alison Williams)