The development of a planned US missile shield would cast serious doubt on future nuclear arms cuts, Russian Foreign Minister Sergei Lavrov was quoted as saying by news agencies on Tuesday. 'If our partners decide to create an American missile-defence system with global reach, this will undoubtedly cast serious doubt on the prospects for further strategic offensive arms reductions,' Lavrov said in an interview with Vesti-24 television, quoted by Russian news agencies. Lavrov's comments underscored a continuing dispute over US missile defence plans that threatens to undermine talks on replacing the 1991 Strategic Arms Reduction Treaty (START), which expires on December 5. On Monday, US President Barack Obama and his Russian counterpart Dmitry Medvedev signed a framework document outlining the principles of a new disarmament treaty to replace START. Russia fiercely opposes US plans to deploy missile defence facilities in eastern Europe, saying they are a threat to its security. The United States says the planned missile shield is not a threat to Russia and is instead meant to protect against Iran. 