ROME, April 24 (RIA Novosti) - Russian-U.S. negotiations on a new strategic arms reduction treaty will take place in May in Washington, a Russian Foreign Ministry official said on Friday.

The Strategic Arms Reductions Treaty (START 1), signed in 1991, obliges Russia and the United States to reduce nuclear warheads to 6,000 and their delivery vehicles to 1,600 each. The treaty expires on December 5 this year.

"The first round of full-scale negotiations between Russia and the United States on a [new] strategic arms reduction treaty will be held in mid-May in Washington," said Anatoly Antonov, director of the Foreign Ministry's department for security and disarmament, who led the Russian delegation at the U.S. Embassy in Rome earlier on Friday.

He said the Rome meeting had a limited format and was of a preliminary nature.

In an interview with RIA Novosti, Assistant Secretary of State Rose Gottemoeller, head of the U.S. delegation, said in Russian: "Yes, it was a quick start."

She stressed that discussion of a new treaty would continue in the course of Lavrov's visit to Washington on May 7.

Earlier in the week, during an official visit to Helsinki, Russian President Dmitry Medvedev said the new deal to replace START 1 must also cover delivery systems.

In 2002, a follow-up agreement on strategic offensive arms reduction was concluded in Moscow. The agreement, known as the Moscow Treaty, envisioned cuts to 1,700-2,200 warheads by December 2012.

Medvedev and U.S. President Barack Obama agreed at their first meeting in London earlier this month on an immediate start to talks on a new strategic arms reduction treaty.