UN Secretary-General Antonio Guterres has urged the United States and Russia to promote efforts for nuclear disarmament. <br/><br/>In his speech in New York on the International Day for the Total Elimination of Nuclear Weapons, Guterres said the states possessing nuclear weapons have a special responsibility to lead by taking concrete steps, including those agreed at various review conferences of the Treaty on the Non-Proliferation of Nuclear Weapons. <br/><br/>Condemning North Korea, the UN Chair said, its provocative nuclear and missile tests are heightening tensions and highlighting the dangers of proliferation.