NATO's chief has welcomed the new arms control agreement between the United States and Russia.
Speaking at a security forum in Brussels Saturday, Anders Fogh Rasmussen said the new treaty could encourage additional cooperation between Russia and NATO countries.
The pact reduces the number of nuclear weapons that the United States and Russia could deploy by about one-third.
The deal still leaves both countries with a nuclear arsenal of about 1,500 warheads.
It must be ratified by the U.S. Senate and the Russian Parliament before it takes effect.
U.S. President Barack Obama called the treaty the most comprehensive arms control agreement in nearly two decades.
A spokeswoman for Russian President Dmitri Medvedev told a Russian news service that the pact reflects both countries' interests.
The two leaders are to sign the treaty April 8 in Prague.
U.S. Secretary of State Hillary Clinton said the pact will give Russia and the United States more credibility in non-proliferation and in dealing with countries like Iran and North Korea on nuclear issues.
Republican Senator Richard Lugar, a long-time champion of nuclear arms control efforts, welcomed Friday's announcement and said he looked forward to working quickly to "achieve ratification."
U.N. Secretary-General Ban Ki-moon called the treaty an "important milestone" and said he believed it would give "significant impetus" to a U.N. conference in May to review the global Nuclear Nonproliferation Treaty.
The new 10-year treaty will replace the Strategic Arms Reduction Treaty (START 1 agreement) signed in 1991 by U.S. President George H.W. Bush and Soviet President Mikhail Gorbachev. That treaty came into force in 1994 but expired in December.
U.S. and Russian negotiators have been working for nearly a year on the new pact.
Verification issues and Russian opposition to U.S. plans for a missile defense system in Europe had been holding up major progress in the talks.
Some information for this report was provided by AFP and AP.