Bucharest - The leaders of NATO and Ukraine on Friday hailed the alliance's promise of eventual membership as a "historic" step and tried to reassure Russia that it was not a threat.

"Our state has the full right to choose its own way" in security matters, but "our Euro-Atlantic interests are not targeted against any third country," Ukrainian President Viktor Yushchenko said at a meeting with NATO's heads of state and government in Bucharest.

NATO leaders announced on Thursday, on the second day of their summit, that Ukraine and Georgia "will become" NATO members, although they gave no timetable for the move and decided not to offer the former Soviet states Membership Action Plans (MAP).

The decision "was not a stand-alone event... (but) the launch of a process that will lead to Ukrainian membership of NATO," the alliance's secretary general, Jaap de Hoop Scheffer, said.

Moscow has long opposed the aspirations of its two former vassals, saying that NATO enlargement in the region would be a direct strategic threat.

But on Friday Scheffer dismissed the concerns raised by analysts that the decision not to offer the former-Soviet duo a MAP was a victory for Russian diplomacy.

"Can there be any misunderstanding of the line we agreed today that Ukraine will become a member of NATO?" Scheffer asked.

"Of course that means that the conditions and criteria will have to be fulfilled, that has always been the case with NATO enlargement, but I stand to be corrected if (the statement on future membership) leaves a shimmer of doubt," he said.

Russia fears that if Ukraine were to join NATO, the alliance would deploy its troops there, directly on the Russian border.

Yushchenko tried to allay those concerns on Friday, saying that "Ukraine has no plans to locate the military bases of any country in the world on its terrain."

No Western state has military bases in Ukraine, but Russia's Black Sea Fleet is based in the Ukrainian port of Sevastopol - a situation set to last until 2017.

Ukraine is already viewed as a key ally by NATO members. It is the only non-NATO state to maintain troops in every one of NATO's missions, a fact both Scheffer and Yushchenko stressed.

While the troop numbers involved are relatively small - 184 in Kosovo and 3 in Afghanistan, for example - Ukraine also provides desperately-needed air transport facilities to both NATO and EU peacekeeping missions around the world.

"The allies highly value, highly value the contribution Ukraine makes to all, I underline, all NATO's operations and missions. I know no other NATO partner in that same position," Scheffer said.

NATO foreign ministers are now set to make a first assessment of Ukraine's and Georgia's progress in key reforms in December.

"I'm sure that in the framework of (the December) meeting, Ukraine will be invited to a MAP," Yushchenko said.

That certainty is not shared by all NATO allies, however. Some point out that public support within Ukraine for NATO membership hovers around 20-25 per cent, and that it would have to rise considerably before the grant of a MAP would be appropriate.

They are also concerned that such a move would antagonize Russia at a time when relations are already strained. (dpa)