Russia and the United States won international praise on Thursday for signing a landmark nuclear arms reduction treaty, but faced calls for further cuts in the former Cold War foes' arsenals.
UN chief Ban Ki-moon hailed "the signing of the New START Treaty as an important milestone in the international efforts to advance nuclear disarmament and to achieve a world free of nuclear weapons".
After months of tough negotiations, Russian President Dmitry Medvedev and US President Barack Obama signed the new Strategic Arms Reduction Treaty in Prague, which is to succeed the expired 1991 START pact.
"This new treaty testifies to the will of the American and Russian presidents to work with determination towards nuclear disarmament," said Foreign Minister Bernard Kouchner of France, the world's third nuclear power.
Under the new treaty, Russia and the United States will be allowed a maximum of 1,550 deployed warheads, about 30 percent lower than a limit set in 2002.
They are also restricted to 700 air-, ground- and submarine-launched intercontinental ballistic missiles that carry warheads.
The UN boss, currently on an official visit to Austria, expressed hope Russia and the United States would continue their efforts toward the "elimination of all nuclear weapons."
"This significant achievement will also help create a positive atmosphere" for next month's review conference of the Nuclear Non-Proliferation Treaty at UN headquarters, he said in a statement.
The new treaty was signed in Prague exactly 12 months after Obama gave a keynote speech in the Czech capital committing the United States to the aim of a world without nuclear weapons.
Obama this week unveiled a new US nuclear posture under which the United States would not stage an atomic attack against a country that does not have nuclear weapons, although he said that did not include Iran or North Korea.
The US leader is to host a nuclear security summit in Washington next week, ahead of the review of the Nuclear Non-Proliferation Treaty in New York in May.
The head of the UN's International Atomic Energy Agency, Yukiya Amano, said that the signing of the new START treaty helped to build momentum behind nuclear non-proliferation efforts.
"Reducing the role and numbers of nuclear weapons is a positive step towards a safe and peaceful world free of nuclear weapons which can impact positively on nuclear non-proliferation efforts," the IAEA director general said in a statement from Vienna.
Also welcoming the new treaty, Polish Foreign Minister Radoslaw Sikorski said in Warsaw: "We hope that the next step will be a reduction in the number of tactical nuclear weapons, especially those deployed near our borders."
Poland had been at the centre of a related dispute between Russia and the United States over plans for a US missile shield.
Obama in September scrapped a plan agreed in 2008 to install the shield in Poland and the Czech Republic that had enraged Russia. The new US missile shield plan remains a deeply contentious issue between Russia and the United States.
Ahead of the signing, Beijing also welcomed the new disarmament treaty and urged Washington to keep reducing its arsenal under its new nuclear policy.
"As the owner of one of the world's biggest arsenals, it is important for the United States to reduce its nuclear arsenal in a responsible manner," foreign ministry spokeswoman Jiang Yu said.
Swedish Prime Minister Frederik Reinfeldt and Foreign Minister Carl Bildt said in a newspaper column the "accord between the presidents Obama and Medvedev is an important step forward, but it is only one of several necessary steps."
"It is ... especially important in our part of the world that the treaty is followed by discussions that aim to powerfully reduce, and in the long run eliminate, so-called tactical nuclear weapons," they wrote in the Svenska Dagbladet daily.
Source: AFP