Tallinn - NATO Secretary General Jaap de Hoop Scheffer restated the military alliance's desire to see Ukraine join its ranks at a high-level conference being held in the Estonian capital, Tallinn, on Thursday.

In his opening speech, de Hoop Scheffer said the talks were taking place at a special moment in NATO-Ukraine relations.

"Let me remind you that at the Bucharest Summit earlier this year, NATO heads of state and government welcomed Ukraine's Euro-Atlantic aspirations for membership in NATO and agreed that Ukraine will become a member of the alliance," he said.

At subsequent press conferences, de Hoop Scheffer told reporters: "The long-standing partnership with Ukraine is not diminishing one iota."

He was joined by Ukrainian Defence Minister Yuri Yekhanurov and US Defence Secretary Robert Gates in stinging criticism of Russia's recent actions, including suspicions that it was attempting to meddle in the affairs of other nations.

"Ukraine must be free to choose its own path and its own future, free from outside interference, and free from outside pressure of any kind in any direction," de Hoop Scheffer said.

Yekhanurov said the regional security environment had changed.

"The world has become less stable and less predictable. The serious developments in Georgia have dispelled the idea that war in Europe is impossible," he said.

"The major issue was what to do next - will we agree to play dangerous imperialistic games of the 19th and 20th centuries and return to spheres of influence or will we follow that basic principle that European democracies have a right to choose their own way to security?" he asked.

Yekhanurov admitted that further progress needed to be made in Ukraine before it could be accepted as a full NATO member and said his country was suffering from an "overdose of democracy" creating political instability. However, he laughed off this week's mass brawl in the Ukrainian parliament as "testimony to fighting spirit of Ukraine."

Gates unleashed the strongest denunciation of Russian actions while urging Ukraine to show the sustained commitment needed to join the alliance.

Gates said countries in Eastern Europe were on edge due to Russia's incursion into Georgia.

"Russia's recent behaviour has been troubling. Within hours of the conclusion of the American election, President (Dmitry) Medvedev responded by threatening to place missiles in Kaliningrad - hardly the welcome a new American administration deserves."

"Such provocative remarks are unnecessary and misguided," Gates added.

Such rhetoric was associated with a bygone era, Gates said, before suggesting that the only real emerging threat on Russia's periphery was Iran.

"I don't think the Iskander missile has the range to get there," he said laconically.

Gates was also less measured in his reaction to the question of Ukraine's and Georgia's NATO Membership Action Plans (MAPs) than de Hoop Scheffer had been. The US diplomat referred back to the Bucharest summit in April when the two countries were granted their MAPs.

"In a way the application has already been signed and sealed at Bucharest," Gates said.

That contrasted with de Hoop Sheffer's earlier statement that NATO foreign ministers will make their first assessment of MAP in December and that it was too early to say what the outcome would be.

"This is a performance-based process, it's not an automatic ticket," de Hoop Sheffer said.

Estonian President Toomas Hendrik Ilves delivered the keynote address to the conference, titled: NATO-Ukraine Relations in an Evolving Security Environment.

"The fact that Ukraine is here today with NATO ministers of defence should convince everyone that NATO understands Ukraine's importance to European security," Ilves said.

"I can assure you that NATO remains committed to the protection of Europe's security. This is why we will never abandon democratic Ukraine - an integral pillar of the European security architecture," he asserted.

Ilves and de Hoop Scheffer also went out of their way to praise Estonia's leading role in the sphere of cyber-security, while Gates confirmed that the US will send a permanent representative to the NATO cyber-defence centre located in Tallinn.

In April 2007, Estonian servers were subjected to a huge cyber-attack in the wake of riots sparked by the relocation of a Soviet-era war memorial.

The manner in which Estonia's cyber-defence structures coped with the attacks, most of which emanated from Russia, gained the Baltic nation a reputation for excellence that resulted in NATO's decision to base its cyber-defence facility in the Estonian capital. (dpa)