MOSCOW, September 3 (RIA Novosti) - A new round of talks on a nuclear arms reduction deal between Russia and the U.S. will take place in Geneva on September 21, the Russian Foreign Ministry's spokesman said on Thursday.

U.S. President Barack Obama and his Russian counterpart Dmitry Medvedev agreed in July in Moscow on the outlines of a deal to replace the 1991 Strategic Arms Reduction Treaty (START-1), which expires on December 5.

"It has been decided that the next round of talks will be held on September 21 in Geneva," Andrei Nesterenko said.

The September meeting will be the sixth such meeting.

Nesterenko said that during the last meeting, the participants discussed the parameters of the new treaty, formulating wording that presidents Obama and Medvedev could both agree to.

"Both parties have begun discussions of the correct text formulation of the agreement being tailored, and working groups have been formed for itemized discussions," Nesterenko said.

The spokesman said Russia was pleased with the "strategic dialogue with the new U.S. administration." He said current dialogue is aimed at "reaching positive results, and has a healthy and pragmatic approach."

Earlier on Thursday Russian Foreign Minister Sergei Lavrov said Russia and the U.S. were making headway on work to have a new nuclear arms reduction deal in place by the time the current treaty expires.

However, Moscow and Washington have yet to agree on reductions in arms delivery vehicles.

"There are a lot of issues that are quite complex in regard to the security of the Russian Federation and the United States, as well as issues of strategic stability," Lavrov said.

"However, we need to work in the timeframe the presidents defined and we will do everything we can to have the new document ready before the expiration of the current START treaty," he said.