US officials are doing negotiations with their Russian counterparts over the renewal of an arms reduction treaty that expires early next month, the State Department said on Monday.

"The negotiating teams are continuing to work very hard in Geneva, they have agreement on a number of issues, but they are also trying to work out some of the areas where they need to come together," State Department spokesman Ian Kelly told reporters.

"We are certainly hopeful about it, that we will be able to have a draft agreement that both sides are comfortable with," he said.

The United States and the former Soviet Union signed in 1991 Strategic Arms Reduction Treaty (START) that expires on December 5, 2009. Under the treaty, Washington and Moscow agreed to cut in their nuclear arsenals and to set limits on long-range missiles.

During their Moscow summit meeting in July, US President Barack Obama and his Russian counterpart Dmitry Medvedev agreed to each reduce their nuclear arsenal to between 1,500 and 1,675 warheads within seven years.