UNITED NATIONS, Feb. 4 (Xinhua) -- UN Secretary-General Antonio Guterres warned on Wednesday that the expiration of New START, the U.S.-Russia nuclear arms reduction treaty, marks a grave moment for international peace and security.

UN Secretary-General Antonio Guterres speaks to the press outside the Security Council Chamber at the UN headquarters in New York, Aug. 31, 2023. (Xinhua/Xie E)