Russia's top general said on Thursday that problems remained in concluding a nuclear arms treaty with the United States, Interfax news agency reported, weeks before the current START agreement expires.

Washington and Moscow both say efforts to agree cuts in their nuclear arsenals are a major step towards "resetting" relations after they cooled to post-Cold War lows in recent years.

"There are a number of problems related to verification, primarily inspections, and some figures, which are currently being discussed at negotiations," Interfax agency quoted armed forces chief of staff Nikolai Makarov as saying.

The Strategic Arms Reduction Treaty runs out on Dec. 5 and negotiators have been working on a new detailed treaty to be signed by U.S. President Barack Obama and Russian President Dmitry Medvedev.

Makarov also said a U.S. mission to the city of Votkinsk, where Russian missiles are manufactured, would have to wind up its activities by Dec. 5.

Traditionally, the Russian military strikes a more cautious note on talks with the United States than the foreign ministry, which has pointed to progress at talks being held in Geneva.

"The U.S. and Russia have made strong progress in living up to their responsibilities as the two leading nuclear powers, and pursuing a new START agreement that will reduce stockpiles and delivery systems," a spokesman for the U.S. diplomatic mission in Geneva said.

Last July, the leaders set out the framework for the new Treaty, which they said should restrict deployed strategic warheads to between 1,500 and 1,675 while limiting the number of delivery platforms to between 500 and 1,100. But two stumbling blocks remain, one linked to restrictions on Russia's mobile Topol-M missiles and the second to the number of missile delivery vehicles both sides can possess, Kommersant newspaper reported, quoting unnamed experts in the talks.

Moscow is rejecting Washington's attempt to restrict the Topol-M mobile ballistic missiles, as the United States does not have equivalent mobile land-based missiles, the paper reported.

It also said both sides remain divided on the number of delivery platforms that can be deployed, with the U.S. suggesting 1,100 and Russia 500, the paper reports.

The separate Moscow Treaty, which limits both sides to no more than 2,200 warheads, will not expire until 2012, but does not contain detailed guidelines, like the 1991 START Treaty on how to verify compliance with the weapons cuts.

Reuters