Moscow said Friday that the world's first nuclear arms deal in two decades would come into force early next month when US Secretary of State Hillary Clinton meets her Russian counterpart in Munich.

A senior Russian official announced the February 5 meeting between Clinton and Foreign Minister Sergei Lavrov only moments after President Dmitry Medvedev put his name on the ratification of the new US nuclear disarmament agreement.

"Today I signed the ratification document on the Strategic Arms Reductions Treaty (START)," Medvedev said at a meeting with top security officials in comments broadcast on state television.

The pact will come into force the moment Clinton and Lavrov swap their respective ratification documents during the annual Munich Security Conference -- an event born in the 1960s at the height of the Cold War.

The exchange of notes will seal a tortuous process that began more than a decade ago but only came to life with US President Barack Obama's arrival in the White House.

The treaty to eliminate some of the world's most deadly weapons is the centrepiece of Obama's vision of a world without nuclear weapons and a landmark feature of his effort to "reset" the previously-stalled relations with Russia.

The new START reduces previous warhead ceilings by 30 percent and limits each side to 700 deployed long-range missiles and heavy bombers.

The original 1991 pact expired at the end of 2009 amid stark differences over how the two sides planned to proceed amid the emergence of smaller nuclear powers and the rise of hard-line regimes.

Many analyst see the new round of cuts as largely symbolic because the chances of these heavy long-range weapons being used today are negligible.

But the pact provides an important starting point for far more pertinent discussions concerning smaller -- but potentially more dangerous -- nuclear weapons and other high-tech arms.

It will restore vital weapons verifications procedures and require the two sides to try and find a compromise over their seemingly irreconcilable differences over the United States' plan to deploy a missile shield in Europe.

START only became a reality after the US Senate and Russia's parliament adopted a series of non-binding amendments that allowed each country to essentially agree to disagree over what the treaty actually says.

Most of the disagreements concern Washington's missile shield idea and plans to develop new space-based weapons that Russia will not be able to match for many more years.

Russia fears that the European defence system may one day be turned into an offensive weapon and demands an equal say in how the shield works.

Medvedev pointed to those disagreements by noting that Russia's parliament had introduced certain amendments "that are commensurate to those made by the US parliament -- they are symmetric."

"They answer the concerns that our deputies shared about how corresponding provisions of the treaty were being interpreted," said Medvedev.

Medvedev and US President Barack Obama signed the new START in Prague on April 8, 2010 as the two sides tried to "reset" relations that soured under the eight-year Republican administration of George W. Bush.

The Obama administration pushed the treaty through a sceptical Senate in December by in part arguing that it would boost the Medvedev presidency and hurt the position of more hawkish forces in the Kremlin.

Medvedev hailed the treaty's ratification Friday as "a very significant event for our country."

But his military lieutenants were busy piling more diplomatic pressure on NATO as it pushes ahead with the shield idea.

Russian General Staff chief Nikolai Makarov admitted that Moscow's joint system proposal has so far fallen on deaf ears.

"But if we are each going to own ABM systems, the consequences will be catastrophic," he told ITAR-TASS.