But it apparently failed to have Moscow agree to a Washington-sponsored agreement that would allow for the interdiction of missiles and other potential components of weapons of mass destruction while they are being transferred at sea or in the air.

US Under Secretary of State for Arms Control John Bolton met Russia's Deputy Foreign Minister Sergei Kislyak for talks focusing on the spread of weapons of mass destruction and the potential threats posed by North Korea and Iraq.

"The United States plans to focus on issues of the non-proliferation of weapons of mass destruction and all issues linked to this," the ITAR-TASS news agency quoted Bolton as saying before the meeting.

He was due to brief reporters on his visit later Thursday.

However Kislyak told the Interfax news agency after the meeting that no agreement had been reached on Russia signing up to Proliferation Security Initiative -- also known as PSI -- proposed by US President George W. Bush last year.

"As to the PSI agreement, we are continuing to discuss this question," Kislyak said.

Russia has argued that the PSI agreement would open the way for unilateral military action from Washington and wants such deals to be negotiated through the United Nations, where it has veto power.

The hawkish Bolton regularly visits Russia, though he is not always well-received here, and has become one of Washington's top pointmen on issues dealing with Moscow's potential military trade and the spread of weapons of mass destruction.

Bolton was one of the key figures who helped negotiate a May 2002 arms reduction treaty signed by Presidents Bush and Vladimir Putin in Moscow that was meant to reduce the two sides' nuclear arsenals by two-thirds over 10 years.

But that treaty -- to Russia's immense displeasure -- now appears to have been dropped as Washington used a legal loophole to ignore the deal.

The United States has since aired plans to develop miniature nuclear weapons, a military potential that Russia does not yet have and which Washington argues are needed for regional conflicts in the post Cold War era.

Iran has remained a sore point in Russia-US relations despite a new wave of cooperation following the September 11 attacks.

Russia's Bushehr nuclear reactor project is frowned on by Washington amid fears that the Islamic state is using it as a guise to develop a weapons program.

Moscow has since appeared to have put the breaks on the project and delivered strong pressure on Iran to submit to open United Nations inspections of its potential military sites.

Iran's first nuclear reactor is now not due to become operational until 2005 -- years after schedule -- in a deal worth nearly one billion dollars (1.2 billion euros) to Moscow that Russian authorities appear to have used several strategies to push back to appease US concerns.

Under US and Israeli pressure, Moscow is demanding that all of the fuel provided for the reactor is sent back to Russia, and has called for a guarantee that the fuel is delivered safely across Iran.

It is now negotiating a new treaty on the fuel's safe return.

WAR.WIRE