MOSCOW - Russia and the United States are close to a deal to cut vast arsenals of nuclear weapons, Russia said Friday, as the world's two biggest atomic powers rush to replace a Cold War treaty that expires at midnight.

The White House and the Kremlin say that finding a replacement for the 1991 Strategic Arms Reduction Treaty, the biggest nuclear arms reduction deal in history, would help to reset relations after the rows of recent years.

Presidents Barack Obama and Dmitry Medvedev had said they intended to find a replacement for the treaty -- known as START-1 -- before it expired on Dec 5.

Now diplomats in Moscow and Washington are talking about finding a deal by the year-end, although it is still unclear when the two presidents could meet for a signing ceremony.

Intensive work on preparations for the signing are coming to a close, the Russian Foreign Ministry said in a statement e-mailed to news agencies. It did not give further details of the talks.

Negotiations between the two sides have been proceeding in Switzerland under unusually tight secrecy. Both parties have committed to a news blackout on details of the talks and even senior embassy officials are not being fully briefed.

The new deal would cut the number of deployed nuclear weapons as well as the submarines, bombers and missiles used to launch them, although the United States and Russia would still have enough firepower to destroy the world several times over.

Differences over exact numbers of warheads and launchers to be cut under the new treaty remain, according to a source familiar with the negotiations, but both sides remain confident they will reach agreement.

The START-1 treaty signed in July 1991 by U.S. President George Bush senior and Soviet leader Mikhail Gorbachev led to the largest bilateral reductions of nuclear weapons in history, though it took nearly a decade of sporadic talks to reach them.
Under the 1991 deal, Russia has more than halved its nuclear arsenal, destroying over 3,000 intercontinental and submarine-launched ballistic missiles, 1,500 missile delivery units, 45 atomic submarines and more than 65 strategic bombers, the Foreign Ministry said.

PRESIDENTIAL SIGNING?

Finding a replacement for the treaty would be filled with symbolism for both Obama, who is due to receive the Nobel Peace Prize on December 10, and for the Kremlin, which is eager to present itself as a world power on a par with the United States.

But diplomats have still given no indication of when the presidents could meet, provoking speculation that talks on a new deal have snagged on a myriad of technical issues such as how to verify compliance.

Russia is insisting on the closure of an observation station about 1,000 km (600 miles) east of Moscow in Votkinsk, where a U.S. team monitors the manufacture of Topol-M missiles, RS-24 missiles and the Bulava submarine-launched missile.

The strong position of the Russian delegation is that the unilateral U.S. military inspection (team) leaves Votkinsk, RIA news agency quoted source close to the talks. The source said the closure had to be included in a new deal.

At a July summit in Moscow, Obama and Medvedev agreed to limit operationally deployed nuclear warheads to between 1,500-1,675 under a new treaty, a cut by about a third from current levels of about 2,200.

Those cuts -- which have to be made within seven years of a new treaty taking effect -- would take the two countries only 25 operationally deployed warheads below the 1,700-2,200 range which they already agreed to reach by 2012 under an earlier pact, the 2002 Moscow Treaty.

They also agreed that the range of limits for strategic delivery systems -- jargon for the missiles, bombers and submarines that launch nuclear warheads -- should be between 500-1,100 units.
(Editing by David Stamp)