Russian President Dmitry Medvedev has signed the ratification of a nuclear arms cut pact with the United States, according to AP. The treaty, known as New START, is a centerpiece of President Barack Obama's efforts to «reset» ties with Moscow. The treaty limits each country to 1,550 strategic warheads, down from the current ceiling of 2,200, and also re-establishes a system for monitoring that ended in December 2009 with the expiration of a previous arms deal. In a statement to his security council on Friday, Medvedev said the pact will take effect when the ratification documents are exchanged by Russian Foreign Minister Sergey Lavrov and American Secretary of State Hillary Clinton.