US President Barack Obama and Russian President Dmitry Medvedev have agreed a new nuclear arms reduction treaty.
In simultaneous announcements in Washington and Moscow, Obama and Medvedev said the deal they sealed in a phone call this morning.
Under the ten-year agreement, each side must reduce its deployed strategic warheads to 1,550 from the 2,200 now allowed.
The deal, which was reached after months of negotiations, will be signed in Prague in the Czech Republic on 8 April.
In Moscow, the Kremlin said 'the presidents agreed that the new treaty marks the transfer of Russian-US cooperation to a higher level in the development of new strategic ties.'
Those views were echoed by the US President. 'We have reached agreement on one of my administration's top national security priorities, a pivotal new arms control agreement,' Mr Obama said at a news conference with Secretary of State Hillary Clinton and Defence Secretary Robert Gates.
President Obama said the treaty would send a clear message that the two countries were committed to preventing nuclear proliferation.
The new pact, due to be signed on 8 April in Prague by the two leaders, replaces the landmark 1991 Strategic Arms Reduction Treaty (START), which expired in December.
The US leader told reporters the deal would help advance his long-term goal of a nuclear-free world which he laid out in a major speech a year ago in the Czech capital.
