Global nuclear security can only be ensured if "all states have effective national [nuclear security] systems", a Russian presidential aide said Sunday.

Sergei Prikhodko, who spoke shortly before the April 12-13 nuclear security summit in Washington, D.C., said Russia maintains its nuclear security at a proper level.

"All nuclear materials and installations on Russian territory are reliably protected," he told journalists.

The U.S. summit, bringing together almost 40 heads of state, will focus mainly on the vulnerability of nuclear materials and securing them against the threat of terrorist acquisition.

The summit comes after the signing on Thursday of a new strategic arms reduction treaty by U.S. President Barack Obama and Russian President Dmitry Medvedev in Prague.

The document that replaced the START 1 treaty, which expired in December 2009, is expected to bring Moscow and Washington to a new level of cooperation in the areas of nuclear disarmament and arms control.

The new strategic arms pact stipulates that the number of nuclear warheads is to be reduced to 1,550 on each side, while the number of deployed and non-deployed delivery vehicles must not exceed 800 on each side.

Under the deal, which will be valid for 10 years unless superseded by another agreement, strategic offensive weapons will not be based on the territory of any third country.