Sergey Lavrov said disagreements over such issues during the past few days had slowed efforts to reach a deal, and he agreed with the White House's assessment that President Barack Obama and Russian President Dmitry Medvedev are not expected to sign a nuclear weapons treaty when they travel to Copenhagen this week.
However, Lavrov also agreed with the White House that the U.S. and Russia continue to make progress on negotiations for a successor to the Strategic Arms Reduction Treaty, known as START I, and that he hopes an agreement would be reached soon.
Russia and the U.S. both want to reach a new accord quickly to give credibility to their efforts to persuade Iran and North Korea to abandon their nuclear programs.
Lavrov blamed the U.S. delegation for slowing negotiations in the past few days. He said the talks in Geneva have now resumed pace, but a deal is unlikely to be reached in time for Obama and Medvedev to sign it when they attend the climate summit in Copenhagen on Friday.
"It's unlikely to happen in Copenhagen," Lavrov told reporters.
He urged the U.S. to agree to deeper cuts in the parties' nuclear arsenals and less intrusive verification and control measures.
"Control measures must be adequate to a new treaty, not the old one," Lavrov said. "They must be lighter and less expensive."
"It's time to get rid of excessive suspiciousness, especially as both presidents have said repeatedly they want to see a new level of U.S.-Russian relations based on trust, mutual respect and equality," he said.
Lavrov said the talks are now moving forward, despite disagreements, and that an agreement could be reached "quite soon." However, he wouldn't say when a new arms deal could be signed.
The new deal will succeed the 1991 START, which expired on Dec. 5. The 500-page document contained a sprawling web of control measures seen as crucial for both nations to keep a wary eye on one another's nuclear stockpiles. Russia sees them as too intrusive and has pushed for softening the verification regime.
Obama and Medvedev agreed in July to cut the number of nuclear warheads each country has to between 1,500 and 1,675 under a new treaty. The two leaders spoke by telephone Saturday to discuss the arms talks.
Lavrov said that Russian and U.S. negotiators have reached agreement on many issues related to the new treaty. "It's important not to go back to what already has been agreed," he said.
The Russian business daily Kommersant reported Thursday that the new deal won't be signed this year as the negotiators are still arguing over weapons numbers and other details. It said the parties are unlikely to iron out remaining differences even next month.
Still, analysts expect Moscow and Washington to reach a deal soon as they need to show to the rest of the world they are moving to cut their nuclear arsenals. Between them, the two countries control 90 to 95 percent of the world's nuclear weapons.
"The new treaty must demonstrate the two powers' readiness to fulfill their obligations" in nuclear disarmament before an international nuclear nonproliferation conference next spring, Anatoly Dyakov, the head of the Moscow-based Center for Disarmament, Energy and Ecology, wrote in Kommersant.
"I think that the treaty will be signed early next year," Fyodor Lukyanov, the editor of Russia in Global Affairs magazine, said on Ekho Moskvy radio. He said that despite technical differences regarding the weapon numbers, Moscow and Washington agree on the need to expedite the signing.