MOSCOW – Vast stockpiles of nuclear weapons amassed during the Cold War could become the catalyst for a thaw in relations this week between the United States and Russia.

U.S. President Barack Obama and Kremlin chief Dmitry Medvedev last month agreed to pursue a deal on cutting nuclear weapons that would replace the 1991 Strategic Arms Reduction Treaty (START I), which expires in December.

The three days of Moscow talks, starting on Tuesday, will have to deal with disputed technical details about nuclear weapons and coincide with NATO war games in Georgia which have angered Russia.

But diplomats said the discussions should help to narrow differences between the world's two biggest nuclear powers, allowing Obama and Medvedev to declare progress when they meet in Moscow on July 6-8.

I think there is a will on both sides to agree a deal, said Dmitry Danilov of Moscow's European Security Studies.

The talks will also be a litmus test showing whether the former foes can work together now there is a new president in the White House and after relations sank to a post-Cold War low during last year's war in Georgia.

Unlike the Bush administration, Obama's negotiating team will be more constructive, there have been signals that they're ready to discuss difficult issues, said Danilov.

Washington and Moscow hope that if they can agree to a successor to START by December, this will strengthen their hand in pushing for an updated Non-Proliferation Treaty.

Obama's administration was credited this month with helping 189 countries agree on the agenda for an overhaul of the treaty.


The U.S. team in Moscow is led by Assistant Secretary of State Rose Gottemoeller and will include officials from the Pentagon and Department of Energy.

Gottemoeller, an expert on Russia who is respected in Moscow, held preliminary talks in Rome last month with Russia's chief negotiator Anatoly Antonov, who heads the Foreign Ministry's department of security and disarmament.

Medvedev and Obama have said the new arms deal should cut stockpiles below those in the 2002 Strategic Offensive Reductions Treaty (SORT), under which both sides are to cut their arsenals to between 1,700 and 2,200 warheads by 2012.

Russia has said it wants to link the nuclear talks to U.S. plans to deploy an anti-missile shield in Europe and has pushed for the United States to put a limit on the number of delivery systems -- the rockets or other means that deliver weapons.

The U.S. has said it will take such vehicles into account but has resisted Moscow's demands that warheads taken off missiles and put into storage should be counted.

Diplomats say that while technical issues remain central to a new agreement, the tone of talks is likely to be constructive.

No formal text is expected to be agreed in Moscow this week, said officials familiar with the agenda.