Top U.S. and Russian arms negotiators will meet in Moscow next week on nuclear weapons cutbacks and missile defense systems, a State Department spokesman said. The U.S. delegation will be led by Undersecretary John Holum and the Russians' by Yuri Kapralov, head of the Russian arms control directorate. The talks Monday through Wednesday follow similar meetings in August in Geneva, Switzerland, said spokesman Philip Reeker. The two sides have been trying to build on a commitment by Presidents Bill Clinton and Vladimir Putin to improve safeguards against accidental launch of nuclear-tipped missiles. At the same time, the United States has been seeking Russian agreement to amend the 1972 Anti-Ballistic Missile treaty for potential deployment of a shield to guard against a missile attack from nations like North Korea or Iran. Russia is strongly opposed to any change in the treaty, and Clinton has decided to leave a decision on such a U.S. system to his successor. The United States also has proposed working on parts of a text for a third Strategic Arms Reduction Treaty, or START III, for further reductions in U.S. and Russian long-range nuclear warheads. The START II treaty, concluded in January 1993, reduced warheads to 3,000-3,500 on each side. Ratified by the U.S. Senate and finally, this year, by the Russian parliament, it has yet to take effect - AP reports.