The radical new treaty would reduce the number of nuclear warheads to 1,000 each.

    Washington - President Obama will convene the most ambitious arms reduction talks with Russia for a generation, aiming to slash each country's stockpile of nuclear weapons by 80 per cent.

    The radical treaty would cut the number of nuclear warheads to 1,000 each, The Times has learnt. Key to the initiative is a review of the Bush Administration's plan for a US missile defence shield in Eastern Europe, a project fiercely opposed by Moscow.

    Mr Obama is to establish a non-proliferation office at the White House to oversee the talks, expected to be headed by Gary Samore, a non-proliferation negotiator in the Clinton Administration. The talks will be driven by Hillary Clinton's State Department.

    No final decision on the defence shield has been taken by Mr Obama. Yet merely delaying the placement of US missiles in Poland and a radar station in the Czech Republic - which if deployed would cost the US $4 billion annually - removes what has been a major impediment to Russian co-operation on arms reduction.

    Any agreement would put pressure on Britain, which has 160 nuclear warheads, and other nuclear powers to reduce their stockpiles.

    Mr Obama has pledged to put nuclear weapons reduction at the heart of his presidency and his first move will be to reopen talks with Moscow to replace the 1991 US-Soviet Strategic Arms Reduction Treaty (Start), which expires in December. Under that pact, the two countries have cut their respective stockpiles from roughly 10,000 to 5,000.

    "We are going to re-engage Russia in a more traditional, legally binding arms reduction process," an official from the Administration said. "We are prepared to engage in a broader dialogue with the Russians over issues of concern to them. Nobody would be surprised if the number reduced to the 1,000 mark for the post-Start treaty."

    Efforts to revive the Start talks were fitful under Mr Bush and complicated by his insistence on building a missile defence shield. "If Obama proceeds down this route, this will be a major departure," one Republican said. "But there will be trouble in Congress."

    The plan is also complicated by the nuclear ambitions of Iran, which launched its first satellite into space yesterday, and North Korea, which is preparing to test a long-range ballistic missile capable of striking the US.

    Mr Obama views the reduction of arms by the US and Russia as critical to efforts to persuade countries such as Iran not to develop the Bomb.