U.S. President Barack Obama and his Russian counterpart Dmitry Medvedev struck an optimistic tone even as they conceded that they were unlikely to sign a deal this year on a successor to an expired nuclear arms control treaty, as they had hoped.
The two leaders met Friday as negotiators are seeking to bridge differences on elusive details of a successor to the Strategic Arms Reduction Treaty.
Obama said Friday that they were "quite close." He had wanted a new deal in place before the end of the year, but that appeared unlikely.
The hold up has denied the White House a quick boost in its efforts to demonstrate improved relations with Moscow. The Obama administration had identified a successor to the START treaty as among the most achievable areas of cooperation with Russia, as it seeks broader help from Moscow on issues including reining in Iran's suspected nuclear ambitions.
Although the 1991 START treaty expired Dec. 5, both countries have agreed to continue to honor its main provisions, pending the completion and legal ratification of a successor treaty.
Emerging from private talks with Medvedev on the sidelines of the U.N. climate conference, Obama expressed confidence that a successor pact will be agreed to in a "timely fashion." Medvedev said technical details still needed to be worked out.
Both leaders made only brief statements to reporters and took no questions. Neither one said anything about a possible timetable for signing a deal.
"We've been making excellent progress," Obama said. "I'm confident that it will be completed in a timely fashion."
Medvedev largely echoed Obama's expressions of optimism.
Despite the hopeful words, a senior administration official familiar with Friday's discussions in Copenhagen said there was no new progress. The official spoke on condition of anonymity because he was not authorized to discuss the matter publicly.
U.S. arms control advocates expressed disappointment.
"The likely failure of the U.S. and Russia to come to an agreement before the end of the year is deeply disappointing," said Daryl G. Kimball, executive director of the private Arms Control Association. He said both sides must show greater flexibility in order to resolve the few remaining issues.
News agencies cited Medvedev aide Sergei Prikhodko as saying a treaty signing will not happen this year. Prikhodko said no signing date was being announced to avoid putting excess pressure on the negotiators, who are meeting in Geneva.
U.S. officials, speaking on condition of anonymity because of the sensitivity of the talks, said negotiations had become hung up on a disagreement over how to monitor the development of new intercontinental ballistic missiles.
Officials said U.S. negotiators would continue working with their Russian counterparts through the weekend. But negotiators plan to break for the Christmas holiday and return to the bargaining table in the new year, a U.S. official said Friday, speaking on condition of anonymity because he was not authorized to speak on the record.
Signed by Soviet President Mikhail Gorbachev and U.S. President George H.W. Bush, that treaty required each country to cut its nuclear warheads by at least one-fourth, to about 6,000, and to implement procedures for verifying that each side was sticking to the agreement.
At a summit in Moscow last July, Obama and Medvedev agreed to cut the number of nuclear warheads on each side to between 1,500 and 1,675 within seven years, as part of a broad new treaty. They initially had instructed negotiators to seek a fully ratified deal by the Dec. 5 expiration.
Associated Press writers Vladimir Isachenkov and David Nowak in Moscow, Eliane Engeler in Geneva and Robert Burns in Washington contributed to this report.