Hopes are rising on both sides that President Barack Obama's visit to Moscow next week will produce a breakthrough in talks on cutting U.S. and Russian nuclear weapons and on helping Washington in Afghanistan, according to Reuters. Officially, neither side has made an announcement but diplomats believe Obama will agree with President Dmitry Medvedev the outline of a deal to reduce the stocks of deployed nuclear warheads to somewhere below 1,700 on each side. "We are confident that we will secure an agreement committing both sides to cutting warheads to fewer than 1,700," one person close to the talks said. Obama and Medvedev gave the go-ahead to talks on a new strategic arms treaty to replace START-1, which expires on Dec. 5, when they met for the first time in London in April. Sergei Ryabkov, a Russian deputy foreign minister, said on Tuesday that progress in the arms talks had been "beyond what was expected when we started". By December, Ryabkov told the state-run RIA news agency, he expected a "solid document with a range of measures for testing and exchange of information...and real reductions in strategic offensive weapons". Estimates of current nuclear stockpiles differ but according to the U.S.-based Bulletin of the Atomic Scientists at the start of 2009 the United States had around 2,200 operationally deployed strategic nuclear warheads and Russia around 2,790. Washington is also optimistic of securing Moscow's agreement to ship lethal military supplies to its troops in Afghanistan across Russian territory -- an urgent priority as existing supply lines across Pakistan become less safe. Diplomats say the two agreements are likely to be the main fruits of Obama's July 6-8 trip to Russia and will be touted as evidence that both sides want to "press the reset button" -- to use Washington's phrase -- on their rocky relations of recent years. Relations between Russia and the United States hit their lowest point since the end of the Cold War last summer over a war in U.S. ally and former Soviet republic Georgia. Russia's decision to send troops and armour deep into neighbouring Georgia in response to Tbilisi's attack on a Russian-supported rebel region angered Washington and led to a suspension of NATO cooperation with Moscow -- now lifted. Both sides are now trying to put that behind them to make progress on nuclear disarmament and other areas -- such as strengthening efforts to halt the spread of nuclear weapons -- where they see a chance of relatively quick agreement. HOST OF DIFFERENCES PERSIST But analysts warn that any prospective deals could yet be torpedoed by a host of differences between Moscow and Washington. The two sides are far apart on U.S. plans to station an anti-missile system in Poland and the Czech Republic, something Russia says threatens its security. Moscow also dislikes U.S. aspirations to bring more former Soviet republics into NATO, an alliance Russia views as a hostile Cold War relic. Russia's ruling elite still smarts at what it sees as U.S. moves to take advantage of its weakness in the chaos that followed the collapse of the Soviet Union and is determined to bargain hard, despite a deep economic recession and continued problems in equipping and training its military. "The biggest deliverable from the summit will be an agreement on the parameters of a START treaty," said Dmitry Trenin, head of the Moscow Carnegie Centre think-tank, during an online conference ahead of Obama's visit. "But START is not a big achievement. It will regulate adversarial relations but on its own it will not bring U.S.-Russia relations to a new level." Moscow and Washington have already agreed in a 2002 treaty to cut their nuclear arsenals to 1,700-2,200 deployed nuclear warheads by 2012, so any further reduction agreed in principle next week is likely to be relatively small. Underlying all the talking next week will also be a gulf in expectations and attitudes between a popular U.S. administration with a big electoral mandate and a fearful, insular Kremlin leadership who see threats all around them. Lilia Shvetsova of Carnegie believes the two sides have a quite different understanding of what it means to "reset" their relations. "For the U.S., this is an instrument to pursue American interests in the nuclear non-proliferation area, in Iran and in Afghanistan," she told the online conference. "For the Russian leadership...they view the reset button as a possibility to prove they have been right on all issues in Russia-America relations and to use the reset button to increase the leverage of Russia and its great power status. "This asymmetry is not a healthy sign."