The pact, which is set to expire next week, regulates the amount of strategic nuclear weapons that Kremlin and Washington can deploy. Once signed by President Vladimir Putin, the deal will be extended for five years.
Russia's upper house of parliament, the Federation Council, has voted to ratify an extension of the New START nuclear arms control treaty with the United States.
Wednesday's vote is seen as a move towards preserving the last major pact of its kind between Russia and the US.
The Kremlin on Tuesday said the two countries had struck a deal to extend the pact, signed in 2010 and set to expire next week, which limits the numbers of strategic nuclear warheads, missiles and bombers that Russia and the United States can deploy.
The lower house, the State Duma, earlier also voted to ratify the extension.
The New START, Strategic Arms Reduction Treaty, is a cornerstone of global arms control.
"The essence of the agreement is to extend it for five years, as it was signed, without any changes," Deputy Foreign Minister Sergey Ryabkov told the State Duma, or lower house.
'Step in the right direction'
Russian President Vladimir Putin hailed the ratification and termed it as the "step in the right direction."
Once it is approved by both houses, draft legislation usually becomes law once it has been signed by Putin.
Ryabkov said the extension had been agreed "on our terms", the TASS news agency reported.
Moscow and Washington had failed to agree an extension under former US President Donald Trump, whose administration had wanted to attach conditions to a renewal that Moscow rejected.
In a Tuesday phone call, Putin and US President Joe Biden agreed that their teams should work urgently to complete the extension by February 5, when the treaty was set to expire.