Russia and the United States will most likely sign a new strategic arms reduction treaty by the end of this year, a Russian political analyst has said.

Moscow and Washington are still negotiating a replacement for the Strategic Arms Reduction Treaty (START I), the basis for Russian-U.S. strategic nuclear disarmament, which expires on December 5.

"The [new] agreement will not be signed on Saturday, but there is a possibility that it could be signed as early as mid-December," Alexei Arbatov, director of the Center for International Security Studies at the Moscow State Institute of International Relations, said during a video conference between Moscow and Washington on Wednesday.

START I commits the parties to reducing their nuclear warheads to 6,000 and their delivery vehicles to 1,600 each. In 2002, a follow-up strategic arms reduction agreement was concluded in Moscow. The document, known as the Moscow Treaty, envisioned cuts to 1,700-2,200 warheads by December 2012.

An outline of the new pact was agreed during the Russian and U.S. presidents'' bilateral summit in Moscow in July and includes cutting their countries'' nuclear arsenals to 1,500-1,675 operational warheads and delivery vehicles to 500-1,000.

Russian and U.S. experts have held several rounds of talks on the new document since July, and have repeatedly expressed hope that the replacement for START I could be ready by December 5 deadline.