Sergei Lavrov at UN office in Geneva (file photo)

Russia's top diplomat says concerns over U.S. plans for a missile shield in Europe could be eased if Russian military officers have permanent access to shield facilities in the Czech Republic.

Foreign Minister Sergei Lavrov spoke Tuesday on Moscow radio.  He said Russia's main concern is in monitoring U.S. guidance radar set for deployment in the Czech Republic to ensure the radar is not aimed at Russian territory.

Lavrov said the demand for Russian access to the radar is a key sticking point in ongoing negotiations with Washington.  U.S. officials have not offered details of disagreements with Moscow.

The U.S. missile defense plans topped the agenda during talks in Russia Sunday between President Bush and his Russian counterpart, Vladimir Putin.

The two leaders failed to reach an agreement, but they agreed to continue working to find a solution.

Washington says the missile shield is aimed at protecting the United States and its allies from attacks by Iran.  Moscow has argued the missile system near its borders is a threat to Russian security.

Some information for this report was provided by AFP, AP and Reuters.