Russia said Wednesday it had notified the United States it no longer wanted to extend a two-decade-old US-funded arms disposal initiative that has helped Moscow decommission thousands of nuclear warheads.

The unexpected announcement came just weeks after the Kremlin asked a key US democracy development programme to leave Moscow in the latest deterioration in relations under President Vladimir Putin's new term.

The so called Nunn-Lugar programme -- named after former Senator Sam Nunn and current member Richard Lugar -- had been due to expire in May 2013 after last being extended in 2006, said Deputy Foreign Minister Sergei Ryabkov.

"The American side knows that we do not want another extension," Ryabkov told Russia's Interfax news agency.

"This is not news to the American side."

The report said Ryabkov was responding to Russian newspaper speculation that the initiative had been shut down as a consequence of the Kremlin's decision to kick out the USAID development programme organised by the US embassy in Moscow.

USAID has been ordered out of the country over accusations it supported opposition leaders who helped organise a wave of demonstrations against President Vladimir Putin's rule.

But Ryabkov said the Nunn-Lugar decision was in no way related to the USAID case.

"There is no connection," he said.

The Nunn-Lugar plan was created in 1992 after the breakup of the Soviet Union -- an era of strong international worries over the fate of the USSR's vast arsenal of nuclear as well as chemical and biological weapons.

Nunn-Lugar helped by doing both the simple and the complex: it started out by installing fences around some of the most dilapidated Russian storage facilities and worked all the way up to arranging actual arms elimination work.

But a large part of the initiative involves simple surveillance -- an agreement letting Washington know how much of each material an ex-Soviet nation has and what progress it is making in its reduction commitments.

Ryabkov suggested that Moscow was starting to feel constrained by the deal because it gave Washington additional access to sensitive information that should be shared only on a mutual basis.

"We are interested in fair, normal and mutually-beneficial cooperation with third parties," the diplomat told Interfax.

He noted that the deal was originally negotiated in a different era when an independent Russia was much poorer and far less able to fend for itself.

"This agreement does not suit us -- especially when one takes new the realities into account," Ryabkov said.

The programme had been hailed as one of Washington's most successful post-Soviet initiatives related to Russia and supported by both Democratic and Republican administrations.

The Kommersant business daily said both the Pentagon and the State Department had been pushing strongly for an extension despite signs of Russia seeking a way out as early as last expiration date five years ago.

The respected paper added that Lugar had himself raised the issue when leading a top US delegations to Moscow this year.

"However, the guests left empty-handed," Kommersant wrote.

"Moscow informed them that it does not see the expedience of extending the agreement."

The programme's website said it has helped Russia organise and pay for the decommissioning of more than 6,000 nuclear warheads as well as ex-Soviet chemical and biological weapon stockpiles.