The United States and Russia have both said they hope to have a new agreement by the end of this year on limiting nuclear weapons.

The timing is right for the two countries to build on the Strategic Arms Reduction Treaty (START), Russian Foreign Minister Sergei Lavrov told the UN Conference on Disarmament in Geneva on Saturday.

"The right moment has come, for the first time since the end of the Cold War, for making real progress in resuming the global disarmament process on a broad agenda."

Russia and the United States hammered out the START I treaty in 1991 and updated it in 2002, but the agreement is due to expire in December.

The original treaty limited each side to 6,000 nuclear warheads, as well as 1,600 missiles and bombers. START II brought the number of warheads down to 3,500.

A successor deal with the U.S. must cover delivery systems as well as warheads, Lavrov said.

On Friday, U.S. Secretary of State Hillary Clinton met with Lavrov for a two-hour working dinner in Geneva and later said reaching a new arms reduction treaty was "of the highest priority."

The new U.S. administration under President Barack Obama has been talking about "pressing the reset button" in its relations with Russia, Clinton said.

Despite disagreements in the past few years, sparked by Russia's invasion of Georgia and the proposed U.S. missile interceptor system in eastern Europe, the two countries plan to start work immediately on reaching a new nuclear treaty, she said.

"We discussed a number of specific issues that we believe are important for us to work together on to make progress. There is no time to waste on a number of these significant challenges, so we will begin to work immediately to translate our words into deeds," Clinton said.

The talks between Clinton and Lavrov were held to lay the groundwork for Obama and Russian President Dmitry Medvedev before they meet for the first time at the Group of 20 summit in London on April 2.