By Oleg Shchedrov and Caren Bohan
LONDON (Reuters) - Russia and the United States will pursue a new deal to cut nuclear warheads, presidents Dmitry Medvedev and Barack Obama said Wednesday, making good on a pledge to rebuild relations from a post-Cold War low.
They said in a joint statement they had ordered negotiators to report first results by July, when Obama will visit Moscow for a summit.
"In the past years, there were strains in relations between our two countries and they were drifting in the wrong direction," Medvedev said after a meeting that found much common ground but also aired frank disagreements, according to U.S. officials.
"This was not in the interests of the United States, Russia or global stability. We agreed to open a new page in these relations, to reset them, given the joint responsibilities of our states for the situation in the world," Medvedev said.
Obama, 47, said he and the 43-year-old Kremlin leader had begun "constructive dialogue" on issues from nuclear proliferation to counter-terrorism to economic stability.
The two leaders were meeting for the first time in London on the eve of a G20 summit to discuss the global economic crisis.
They acknowledged lingering differences over last year's Russia-Georgia war and over U.S. proposals to base parts of a missile shield in Eastern Europe, something Moscow considers a threat to its security.
A U.S. official said Obama told Medvedev "very forcefully" that Washington would never recognise South Ossetia and Abkhazia, two breakaway pro-Russian regions of Georgia that Moscow has backed as independent states since the August war.
Obama also made clear that Moscow's view of the former Soviet states as its special sphere of influence was "not a 21st century idea," the official said.
But U.S. officials said the two leaders had set an ambitious agenda, agreeing to cooperate on international issues from Afghanistan to Iran's disputed nuclear program and expressing concern about a forthcoming North Korean rocket launch.
NO "BUDDY-BUDDY"
The two men smiled but looked slightly awkward when they appeared together before reporters.
That marked a contrast with the matey style displayed by their predecessors: George W. Bush said he looked Vladimir Putin in the eye and "was able to get a sense of his soul" when they met for the first time in 2001.
"Our strategy is different from that. Our strategy is to develop an agenda based on interests, also accentuating where we disagree but not to make the goal of these meetings to establish some buddy-buddy relationship," one U.S. official said.
The planned arms deal gives both sides a chance to "press the reset button" on their relations, a phrase coined by U.S. Vice President Joe Biden in February.
"The new agreement will mutually enhance the security of the parties and predictability and stability in strategic offensive forces," they said in a joint statement.
"We are ready to move beyond Cold War mentalities and chart a fresh start in relations between our two countries."
The proposed arms deal would go beyond the 2002 Strategic Offensive Reductions Treaty (SORT), which committed both sides to cutting arsenals to between 1,700 and 2,200 warheads by 2012.
It would replace the 1991 Strategic Arms Reduction Treaty (START 1), which led to the biggest ever bilateral cuts in nuclear weapons, but will expire in December.
According to the Carnegie Endowment for International Peace, Russia currently has 3,113 strategic warheads compared with 3,575 for the United States. (www.carnegieendowment.org)
Russia sees START 1 as the cornerstone of post-Cold War arms control and believes that letting it lapse with no replacement could upset the strategic balance.
Among difficult issues to be negotiated will be differences over the way warheads are counted, and whether warheads removed from missiles should be stored or destroyed.
Moscow wants to link the successor treaty to the proposed U.S. missile shield plan, which it strongly opposes. U.S. support for admitting Ukraine and Georgia to NATO has also been viewed by Russia as a threatening expansion into former Soviet territory.
(Reporting by Oleg Shchedrov, Caren Bohan and Matt Spetalnick, writing by Mark Trevelyan; editing by Janet McBride)