Russia's foreign ministry spokeswoman says Turkey's shooting down of a Russian warplane near the Syrian border last week has put a strain on Syrian peace talks.

Maria Zakharova told The Associated Press on Tuesday that the incident, in which two Russian servicemen were killed, not only strained the previously warm ties between Russia and Turkey but also "made the Vienna talks difficult" and made Moscow more determined to get other parties to agree on a list of "terrorist" groups in Syria before the next round of talks. Without that, Zakharova said, a joint action in Syria is impossible.

A Russian presidential adviser on Monday reported progress on coordinating the list. Zakharova said on Tuesday Moscow has no timeline in mind by which the agreement on it should be reached.