 Stalin initially agreed to send military equipment and ammunition, but warned Zhou that the USSR's air force would need two or three months to prepare any operations and no ground troops were to be sent.In a subsequent meeting, Stalin told Zhou that he would only provide China with equipment on a credit basis, and that the Soviet air force would only operate over Chinese airspace after an undisclosed period of time.Stalin did not agree to send either military equipment or air support until March 1951.