Russia and the United States seemed to be edging towards the signing of a new nuclear weapons treaty later this month, officials in Moscow said.

"Intense work is under way on the strategic arms cut treaty," Kremlin aide Arkady Dvorkovich was quoted saying by the Interfax news agency. "We intend to finish these negotiations [in the month]."

The announcement was made after officials from both countries confirmed that U.S. President Barack Obama and his Russian counterpart Dmitry Medvedev spoke by telephone over the weekend about the negotiations.

Both leaders agreed to extend the talks, but officials refused to elaborate. The Strategic Arms Reduction Treaty expired Dec. 5.

Obama and Medvedev agreed in July to reduce each of their countries' deployed strategic nuclear arsenal to between 1,500 and 1,675 weapons within a span of seven years, as part of a revised agreement being hammered out by both sides.

The expired treaty, signed by Soviet President Mikhail Gorbachev and U.S. President George H.W. Bush, required each side to reduce their nuclear warheads by about 6,000 and proceed with cross verifications to confirm that both sides were adhering to the agreement.

Interfax agency quoted a Russian military-cum-diplomatic source as saying that the agreement would be signed by the two leaders at a European capital in the latter part of December.

The ratification of the new treaty will take about a year. During that period, a bilateral commission is set to be established to resolve disputes that may emerge, Interfax reported, citing the military-cum-diplomatic source.

In their weekend telephone call, the two leaders "continued a detailed exchange of opinion about the results achieved and the prospects of completing work on a document that is of vital importance for strategic stability in the world," a Kremlin statement said.

The two presidents "noted with satisfaction that the work of the delegations of both countries … has an intense and purposeful character that makes it possible to speak of substantial progress in the negotiation process," it added.

Reports suggest that the areas of contention are likely to focus around terms for confirming both sides' compliance with the deal and how many warhead delivery vehicles would be allowed on each side.

Medvedev will travel to Copenhagen for the final stages of the U.N. climate talks on Thursday and Friday, when the U.S. president is due to arrive to attend the conference.

Delegations in Geneva have been working on the revised treaty for months. Despite the intention to limit their arsenal, analysts say each country will retain enough firepower to destroy the world several times over.