ST PETERSBURG, Russia - Russia is still willing to offer the United States joint use of a radar station in Azerbaijan to combat hostile missiles despite Washington's signal it will press ahead with its plan of using Poland and the Czech Republic, a Russian official said on Saturday.

President Vladimir Putin, keen to avoid Washington placing its missile defence shield in Central Europe where Moscow says it could threaten Russian security, on Thursday surprised the United States with a rival offer.

Suggesting both sides instead used the Russian-controlled Qabala radar station in Azerbaijan, Putin said this would make the Polish and Czech elements of the missile shield unnecessary, and that Moscow would then not retarget its own missiles towards Central Europe.

President George W. Bush did not comment directly on the Russian offer to use Qabala during a visit to Poland on Friday, but signalled Washington would press ahead regardless with its plans to locate the shield in Central Europe.

Asked about the U.S. reaction to Russia's offer, First Deputy Prime Minister Sergei Ivanov told a news conference in St Petersburg: "Of course (the Russian initiative) remains on the table."

Ivanov, a former defence minister, is considered a leading contender to succeed Putin in elections next March.

He reiterated that using Azeri-based radar would be more effective than operating radar in Central Europe because it could pick up hostile cruise missiles as well as intercontinental missiles.

"In my opinion, Russia's suggestion regarding the use of Qabala radar station ... is the most effective from the point of view of control over launches of any missiles from the vast southern strategic direction."