Now approved by both countries' legislatures and presidents, the new Strategic Arms Reduction Treaty between the United States and Russia is set to come into force within weeks.
Obama and Medvedev signed the treaty last April
The Russian upper house of parliament voted on Wednesday to ratify a landmark treaty with the United States to cut down both countries' stockpile of nuclear weapons, clearing the last legislative hurdle for the treaty to come into force.
All 137 senators in the Federation Council approved a bill necessary to ratify the new Strategic Arms Reduction Treaty, a successor to a similar 1991 treaty between the former Cold War enemies.
Russian President Dmitry Medvedev is to sign the ratification bill soon, and the treaty comes into force with the exchange of documents with the US, expected within weeks.
The Duma had given its own final approval to the treaty on Tuesday
The upper house's approval was the last legislative obstacle to the new START, after the Duma, the lower house, had given its third and final vote of approval to the treaty on Tuesday. The United States Senate voted to ratify the treaty in late December.
Big cuts to arsenals
US President Barack Obama and Russian President Dmitry Medvedev signed the treaty in Prague on April 8, 2010, after long negotiations.
The treaty limits each country to 1,550 strategic warheads, a 30 percent reduction from the current cap, and reintroduces a monitoring system that expired in December 2009 along with the 1991 START.
Speaking in his annual State of the Union speech on Tuesday, Obama hailed American non-proliferation efforts and said the country had "reset [its] relationship with Russia."
"American leadership can also be seen in the effort to secure the worst weapons of war," he said. "Because Republicans and Democrats approved the new START Treaty, far fewer nuclear weapons and launchers will be deployed."
Obama said the US had 'reset' its relationship with its old foe
NATO Secretary General Anders Fogh Rasmussen, who has made improving ties with Russia a cornerstone of his office, also praised the new START ratification as "good news for international security."
"I also hope that the political momentum generated by this treaty will help Allies and Russia to make concrete progress in their strategic partnership, including in the field of missile defense," he said in a statement.
Following the passage of the law through the Duma the day before, Obama had congratulated Medvedev and said that both presidents pledged to "build on this progress as they continue their close partnership in 2011."
Amendments to bills
In a potentially foreboding sign of skepticism, the Duma amended its ratification bill to stress Russia's right to withdraw from the new START if it feels threatened by US military actions.
Moscow sees a missile shield in Eastern Europe promoted by Washington as a potential threat, though the US says the shield is to counter threats from Iran.
US senators also made their own non-binding amendments to the treaty, including a recommitment to the missile defense shield and a modernization of the current nuclear arsenal.
Author: Andrew Bowen (AFP, AP, Reuters, dpa)
Editor: Michael Lawton