ST. PETERSBURG, June 25 (RIA Novosti) - NATO's secretary general said Monday he did not expect a quick solution to Russia's concerns over the Western alliance's enlargement.

Speaking in St. Petersburg at a conference to mark the 10th anniversary of cooperation between NATO members and Russia, Jaap de Hoop Scheffer denied that the body's enlargement was a threat to Russia's interests.

Russia has been alarmed by the continued emergence of new NATO bases along its borders, as the alliance has admitted 10 former Eastern Bloc states, including three ex-Soviet Baltic republics, since the fall of Communism in Europe.

De Hoop Scheffer said NATO was keeping its doors open, but that no talks on membership were currently being held with Russia's former Soviet ally Georgia.

Moscow has been unnerved by the United States' strong backing of anti-Kremlin forces in ex-Soviet Ukraine and Georgia, and the Caucasus nation's NATO aspirations, as well as by Washington's plans to deploy its missile shield elements in Poland and the Czech Republic.

The U.S. says a radar and a missile base in Central Europe are needed to counter possible missile attacks from North Korea and Iran, but Moscow has dismissed this explanation, calling such a threat nonexistent, and insisting that the missile shield plans threaten Russia's national security.

In an interview in Russia's second city with radio station Ekho Moskvy later Monday, De Hoop Scheffer dismissed Russia's fears about the planned missile defenses in Europe, saying it was obvious that ten ballistic missiles to be placed in Poland would not pose any threat to Russians.

He called on Moscow to engage in open and transparent dialogue on the matter, and said the problem would be discussed by President Vladimir Putin and George W. Bush in the United States on July 1-2.

The secretary general also said relations between Russia and the alliance had not deteriorated, despite what he called misunderstandings, and insisted that Cold War hostilities were firmly in the past.

Moscow and NATO signed a founding act to form a NATO-Russia permanent joint council ten years ago. The current cooperation forum, the NATO-Russia Council, was set up five years ago to implement projects of common interest, which include crisis management, non-proliferation, rescue efforts, and new challenges. The council does not give Russia a veto right in NATO's decisions.

The NATO chief told the radio station that NATO and Russia needed each other and should continue tackling their differences. He also hailed the sides' cooperation in dealing with the aftermath of man-made disasters, and in fighting terrorism.

De Hoop Scheffer said he hoped a council meeting in Moscow Tuesday would help it step up teamwork, as the members were expected to adopt important decisions and outline further cooperation guidelines.

An additional problem overshadowing cooperation between Russia and NATO is the bloc's refusal to ratify an updated version of the Soviet-era Conventional Forces in Europe Treaty (CFE), aimed at regulating the deployment of non-nuclear weapons on the continent.

President Vladimir Putin has threatened to impose a moratorium on Russia's participation in the crucial arms reduction accord, linking ratification delays to the planned deployment of the missile shield in Europe and the expected opening of new NATO bases in Bulgaria and Romania.

NATO states have argued said Russia should first withdraw its troops from Moldova and Georgia before the alliance's members ratify the amended CFE treaty, while Moscow insists these are unrelated issues.