UNITED NATIONS, Feb. 5 (Xinhua) -- UN Secretary-General Ban Ki- moon on Saturday hailed the entry into force of the new START nuclear arms treaty limiting the number of atomic warheads in the United States and Russia, saying that its coming into effect "will inspire further action towards creating a safer and more secure world for all."

Ban, who is visiting Germany, said in a statement issued here that "I welcome the entry into force of the new START Treaty between the Russian Federation and the United States."

"Bringing the Treaty into operation fulfills one of the commitments agreed to at the 2010 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons," the statement said.

Russian Foreign Minister Sergei Lavrov and U.S. Secretary of State Hillary Clinton on Saturday exchanged ratification documents at a conference on the sidelines of the 47th Munich Security Conference.