UN Secretary-General Ban Ki- moon Tuesday welcomed the release of new Nuclear Posture Review by the United States, calling it 'a timely initiative.' In a statement issued by his spokesperson, Ban said he welcomed President Obama's reaffirmation of his commitment towards a nuclear-free world. 'Following the recent successful conclusion of negotiations between the Russian Federation and the U.S. for a successor agreement to the Treaty on the Reduction and Limitation of Strategic Offensive Arms (START), the release of this new Nuclear Posture Review is a timely initiative in that direction,' Ban said. He expressed the hope that this 'will help keep the recent positive momentum' in the lead up to the upcoming Nuclear Security Summit in Washington D.C. and the Review Conference of Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT Review Conference) at the UN headquarters in May. 