Russia and the United States are on track to renew a treaty that envisages the reduction of nuclear arsenals on both sides, a Kremlin official said at a policy conference in Morocco.

Washington and Moscow have been seeking to agree on a replacement for the Strategic Arms Reduction Treaty known as START-1, before it comes to an end on December 5.

The landmark 1991 treaty led to steep cuts in the two sides' nuclear weapons.

US President Barack Obama and his Russian counterpart Dmitry Medvedev agreed in July on the generalities of a preliminary deal to replace the START-1, but negotiators are still working through several technical issues.

"We are still optimistic about ... signing a new agreement this year which will imply huge progress for the world in this matter," Arkady Dvorkovich, a top adviser to Medvedev, said at a World Policy Conference in Marrakesh late on Saturday, Reuters reported.

"We have a very good and constructive dialogue right now on this matter. I think the obstacles are mostly technical and we can complete in time," he said.

Analysts maintain that Obama's decision to scrap a bush-era missile defense shield plan in Eastern Europe may have facilitated talks on nuclear arms reductions treaty.

The missile shield project, if deployed, would have installed a radar base in the Czech Republic and interceptor missiles in Poland.

Moscow was against the missile shield plan as it perceived the project as a threat to its own security.

RB/MMN