Moscow is ready to study the U.S. initiative on further cutting nuclear arsenals when it formally receives a proposal from Washington, Russian Foreign Ministry said Thursday.

"We haven't received so far the particular proposals on further reductions of our strategic nuclear arsenals. If such proposals come, we will certainly study them carefully," the ministry's spokesman Alexander Lukashevich said in an online comment.

For Russia, the priority has been full implementation of the U.S.-Russia new Strategic Arms Reduction Treaty (START), he reminded.

"After the Treaty implementation we would be ready for possible further steps toward nuclear disarmament," he added.

Lukashevich stressed Moscow considered any proposals affecting strategic stability in connection with other U.S. moves in the issues of disarmament.

He mentioned the deployment of the U.S. anti-missile defense shield and lack of progress in the ratification by the U.S. and 44 more countries of the Comprehensive Nuclear Test-Ban Treaty.

Lukashevich also pointed at Washington's reluctance to rule out the possibility of deployment of weapons in space.

The new START that U.S. President Barack Obama signed with Russia in 2010 commits Washington and Moscow to cut their warhead ceilings by 30 percent over the next 10 years from the current 2,200 to 1,550 and limit each side to 700 deployed long-range missiles and heavy bombers.

On Tuesday, Obama in his State of the Union address pledged to work with Russia to further reduce the nuclear weapons stockpiled by the two countries.