He was responding to journalists' questions here about seven new countries, including former Soviet constituent republics, joining the North Atlantic alliance Monday, thus extending it right up to Russian frontiers.

"The discussions we have had with Russia have been quite straightfoward and quite non polemical," he said: "There is no sense of crisis at all between NATO and Russia over enlargement."

His remarks contrasted with concern expressed by Moscow about planned NATO air patrols in the Baltic area close to Russian territory.

NATO warplanes will start to patrol Baltic airspace next Monday, Latvian Defence Minister Atis Slakteris said Thursday, confirming alliance plans that have edged up tensions with neighbouring Russia.

But Burns took a studiously relaxed attitude, stressing that NATO and Russia had a strong partnership.

"Russia understands that NATO enlargement is something that is not at all aimed in a negative way at Russia," he said. "What we have decided and of course communicated here at NATO to the Russian Federation is that we will be extending our air defence regime to the new members."

Burns confirmed that NATO planned to station aircraft in Lithuania to protect the air space of Lithuania, Estonia and Latvia: "In the case of the Baltic countries the plan is to station four fighter aircraft in Lithuania."

The three Baltic states Lithuania, Latvia and Estonia, former Soviet constituent republics, are joining NATO together with former Soviet bloc states Bulgaria, Romania and Slovakia, and Slovenia, once part of Yugoslavia.

The Baltic air defence decision had been entirely transparent to Russia which had been fully briefed, Burns said:

"It in no way represents any kind of a negative signal to the Russian Federation by NATO nor of course does it represent any threat."

"NATO has no plans to station substantial forces in any of the countries that border Russia," he added: "I sense no problem about this whatsoever."

Russia is deeply unhappy about NATO's move to station warplanes in Estonia, Latvia and Lithuania.

The Moscow foreign ministry said Wednesday that such plans were not in line with the spirit of partnership which developed between NATO and Russia in the 1990s after the end of the Soviet Union and communist power.

After spending years fruitlessly trying to block the expansion of the military alliance up to its borders, Russia has come out on the offensive, with Defence Minister Sergei Ivanov saying Thursday he may order a nuclear build-up in response to NATO's Baltic operations.

Moscow fears that flights over Estonia, Latvia and Lithuania would enable the alliance to spy on its defences.

Ivanov said his government would be seeking explanations from NATO Secretary General Jaap de Hoop Scheffer on his next visit to Moscow.

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