Brussels - Russia is welcome to send observers to a set of NATO military exercises in Georgia which have provoked outrage in Moscow, but it has so far shown no interest in doing so, NATO's top spokesman told journalists on Wednesday.

"If Russia chooses to send observers, I think the alliance would look on it quite positively," James Appathurai said in Brussels.

But while all NATO's formal partner countries, including Russia, were invited to join the exercise, Russia did not take up the invitation or attend the planning conferences, Appathurai said.

NATO countries and partners from states including Armenia, the United Arab Emirates, Serbia and Kazakhstan are set to stage two exercises in Georgia from May 6 to June 1.

The first, involving some 650 soldiers, is a headquarters simulation of a UN-mandated mission. The second, including some 450 troops, is to be a field exercise simulating the defence of a peace operation against a terrorist attack, Appathurai said.

Russia, which invaded Georgia in August and which bitterly opposes the country's rapprochement with NATO, reacted furiously to the proposed exercise, which was planned before the Georgian war.

Russia's ambassador to NATO, Dmitry Rogozin, reportedly wrote to NATO Secretary General Jaap de Hoop Scheffer last week demanding that the exercise be cancelled.

"The Secretary General has taken good note of the letter. The bottom line is that the exercise will go forward," Appathurai said.

"It is a long-planned exercise, it is perfectly legitimate and it serves a valid purpose," he said.

In the wake of the Georgian war, NATO froze formal ties with Russia, a decision it reversed in March. The two sides are set to hold their first formal meeting at the end of April. (dpa)