But Russia's top general, while predicting the treaty could be signed in early April, suggested the nations are at odds over how it should handle the divisive issue of missile defense.
US Secretary of State Hillary Clinton said in Moscow on Friday that the Cold War foes were "on the brink" of agreement on a successor to the expired 1991 Strategic Arms Reduction Treaty (START 1), which expired in December.
The arms pact, the subject of months of negotiations in Geneva, is a crucial element of efforts to get Russian-American relations back on track after years of tension.
State-run RIA quoted Russian Deputy Foreign Minister Sergei Ryabkov as saying on Monday: "We are on the verge; I think that this business will be wrapped up in the coming days." Once agreed, the treaty must be signed by Presidents Barack Obama and Dmitry Medvedev and ratified by lawmakers in Russia and the United States to take effect.
Gen. Nikolai Makarov, chief of the general staff of the Russian armed forces, in an interview posted on the website of the government newspaper Rossiiskaya Gazeta on Monday, said the treaty might be signed "in the first days of April." But Makarov suggested negotiators had not yet agreed on how the pact will address missile defense, a cause of deep distrust between Russia and the United States in recent years.
"It is about 95 percent ready, certain points remain to be agreed. Including for us to receive fundamental agreement from the Americans to include the issue of missile defense in the treaty," Makarov was quoted as saying.
He repeated the Russian argument that unless they are limited by treaty, potential US missile defense facilities in Eastern Europe could upset the strategic balance set in the START successor pact and weaken Russia.
Makarov's remarks seemed to contradict Russian Foreign Minister Sergei Lavrov, who suggested recently that Moscow was satisfied with the way the treaty will deal with missile defense.
In a joint understanding last July, Obama and Medvedev agreed the pact would include a provision on the "inter-relationship" between offensive and defensive weapons.
But any rules limiting US missile defense plans could jeopardize the treaty's chances of ratification by the US Senate.
Improving ties is a major goal for Obama, who is seeking stronger Russian support in defeating the insurgency in Afghanistan and reining in Iran's nuclear ambitions.
The July joint understanding said that the new treaty would reduce operationally deployed nuclear warheads to between 1,500 and 1,675 each.
The most recent treaty cutting the Russian and US arsenals of offensive nuclear weapons, signed in 2002, limited them to a maximum of 2,200 warheads each by 2012.
