NATO Secretary General Jens Stoltenberg has said the alliance considers it necessary to maintain contact with countries conducting ground military operations in Syria. Speaking at the annual conference of the Norwegian Atlantic Committee in Leangkollen on Monday, he added that Turkey had informed NATO about its offensive in Afrin, Syria, and would continue to do so, TASS reported. Such contact is a safeguard against representatives of the same coalition fighting each other, the NATO chief was quoted as saying.