US missile defense plans are a threat to Russian national security and have slowed down progress on a new arms control treaty with Washington, Russia's top military officer said Tuesday.Gen. Nikolai Makarov said that a revised US plan to place missiles in Central Europe undermines Russia's national defense, rejecting Obama administration promises that the plan is not directed at his country."We view it very negatively, because it could weaken our missile forces," Makarov, who is the chief of the Russian military's General Staff, said in televised remarks.Makarov's comments are the strongest yet on the revamped US effort and signal potential new obstacles to an agreement on a new nuclear arms reduction treaty to replace the 1991 Strategic Arms Reduction Treaty that expired Dec. 5.The US has insisted that the missile defense plans should be separate from talks to forge a new agreement on cutting the two nations' nuclear arsenals.Moscow and Washington hoped that they would sign a new treaty by the end of December, but talks have dragged on.US President Barack Obama's decision to scrap the Bush administration plans for missile defense sites designed to shoot down long-range missiles from rogue states such as Iran drew praise from the Kremlin, which had fiercely opposed the earlier plan as a threat.In December, Moscow urged Washington to share detailed data about the reconfigured sea- and land-based systems to replace the old plans.Russian officials at first reacted calmly to US plans to deploy Patriot missile systems in Poland, but have grown increasingly critical in recent weeks.And Romania last week approved a proposal to place anti-ballistic missile interceptors in the country as part of the revamped American missile shield.Experts have said the new plan is less threatening to Russia because it would not initially involve interceptors capable of shooting down Russia's intercontinental ballistic missiles.Asked Tuesday about the plans in Romania and Poland, Makarov called the US missile defense plans a threat."The development of missile defense is aimed against the Russian Federation," he said.Makarov said that the planned US missile shield must be part of US-Russian talks on a successor to START. He said that the US refusal to include missile defense in the talks had hampered progress."The treaty on strategic offensive weapons we are currently working onmust take into account the link between defensive and offensivestrategic weapons," Makarov said. "This link is very close, they areabsolutely interdependent. It would be wrong not to take the missiledefense into account."Russia's Prime Minister Vladimir Putin warned the US last month that itmust share information about its missile defense plans if it wantsRussia to provide data on its new weapons.