MOSCOW Russia and the United States are very close to resolving all remaining questions on a new treaty to slash vast Cold War arsenals of nuclear weapons, the Russian Foreign Ministry said on Friday.
"We count on resolving all the remaining questions in the very near future, if not hours," Russia's Foreign Ministry spokesman Andrei Nesterenko told reporters.
The world's two largest nuclear powers have been trying to find a replacement for the 1991 Strategic Arms Reduction Treaty (START-I), the biggest pact to cut nuclear weapons in history.
A senior U.S. official said in Washington on Thursday that U.S. President Barack Obama and Russian President Dmitry Medvedev could reach an agreement in principle in Copenhagen on Friday, leaving negotiators to finalize a deal later.
The two leaders will meet in the Danish capital on the sidelines of a global climate change conference.
Nesterenko declined to confirm a report from the Interfax news agency that said the negotiators had reached agreement on the outline of a new treaty.
Interfax quoted an unidentified diplomatic source as saying: "The provisions of a new START agreement are agreed and there will be an official announcement in the near future."
Russia called on Thursday for simpler verification procedures for planned cuts in nuclear weapons arsenals, while Washington insisted it wanted a deal that worked for both former Cold War foes.
The U.S. official said there was little chance the leaders would be ready to sign a finished accord in Copenhagen.
"But if the presidents are able to come to terms on the remaining verification issues, it might be possible to reach an agreement in principle which will still require the negotiating teams to finalize," the official said.
The White House has said "good progress" was being made in U.S.-Russian negotiations in Geneva despite signs of tension.
"It's high time to get rid of excessive suspiciousness," Russian Foreign Minister Sergei Lavrov told reporters in Moscow on Thursday.
Talks on a replacement for START-I had stumbled in recent weeks, but both sides had said they expected an agreement soon.
Obama and Medvedev had wanted a new treaty by December 5, but the deadline passed and the old accord was extended indefinitely while negotiators in Geneva tried to forge a new pact.
Tensions came to the surface on Thursday.
"In the last couple of days we have noticed some slowing down in the position of U.S. negotiators in Geneva," Lavrov said. "They explain this by the need to receive additional instructions. But our team is ready for work."
White House spokesman Robert Gibbs denied Washington was dragging its feet but said: "We want something that works for both sides. We're going to work on this agreement until we get it right ... it doesn't make sense to get something just for the sake of getting it if it doesn't work for both sides."
Both sides say finding a replacement to the START-I treaty would help "reset" relations between Moscow and Washington that had sunk to a post-Cold War low in recent years.
The START-I treaty, signed in July 1991 by U.S. President George Bush senior and Soviet leader Mikhail Gorbachev, took nearly a decade to achieve but resulted in both Russia and the United States more than halving their nuclear arsenals.
Obama and Medvedev said in July they wanted a new treaty that would reduce operationally deployed nuclear warheads to 1,500 to 1,675, a cut of about a third from current levels.
They also agreed that strategic delivery systems -- the missiles, bombers and submarines that launch nuclear warheads -- should be limited to between 500 and 1,100 units.
Precise figures on deployed nuclear weapons are secret, but the U.S.-based Bulletin of the Atomic Scientists estimated at the start of 2009 that the United States had about 2,200 operationally deployed nuclear warheads and Russia about 2,790.
(Additional reporting by Alister Bull in Washington; Editing by Michael Stott and Paul Taylor)