NATO will soon hold its first formal talks with Russia since 2014, its head said Friday, signalling a thaw in ties deeply strained by the Ukraine crisis.

A meeting of NATO and Russian ambassadors will take place in the next two weeks at the US-led alliance's Brussels headquarters, Secretary General Jens Stoltenberg announced in a statement.

NATO envoys and their Russian counterparts had met regularly until the Ukraine crisis plunged relations with Moscow into a deep freeze reminiscent of the Cold War.

They last convened in June 2014 amid mutual recriminations over who was to blame, with NATO incensed by Moscow's annexation of Crimea in March that year.

Stoltenberg said the meeting would focus on the Ukraine crisis and "the need to fully implement" the Minsk ceasefire accords, which have produced a very tenuous calm in eastern Ukraine where Russia backs pro-Moscow rebels.

The two sides will also look at military activities, "with particular focus on transparency and risk reduction," plus the situation in Afghanistan and "regional terrorist threats," he said.

He said the meeting represented a continuation of a political dialogue as agreed by NATO leaders but warned "there will be no return to business as usual until Russia again respects international law."

Stoltenberg has always insisted the NATO-Russia council remained open as a channel of communication despite the breakdown in relations sparked by Russia's intervention in Ukraine.

A NATO official told AFP that "in difficult times it is good to talk. It shows we are committed to continue the political dialogue."

The official, who asked not to be named, said Stoltenberg had discussed the issue with Russian Foreign Minister Sergei Lavrov when they met in Munich in February.

There will now be further consultations to fix a date for the meeting, the official added.

- Rivals or partners? -

The Ukraine crisis sparked a major re-think within NATO which was taken by surprise over how quickly events unfolded in early 2014.

More worrying still, Russian President Vladimir Putin appeared to be way ahead of the curve in hybrid warfare, exploiting conventional military and social media assets to destabilise the Ukraine government as the rebels consolidated their position.

In response, NATO leaders agreed what Stoltenberg says is the biggest military revamp since the end of the Cold War to make sure Putin does the get the drop on them again.

That means a commitment to spend a minimum of two percent of annual economic output on defence and putting air, sea and land resources into eastern Europe to reassure newer NATO allies there they will not be left in the lurch.

After the Cold War, most of the 28 NATO members let defence spending fall sharply and it has taken painful political decisions to reverse course.

If a more aggressive Russia is a concern, NATO also recognises Moscow cannot be ignored in many international issues, particularly the terror threat from the Islamic State (IS) group.

In September, Russia launched a massive military campaign to support long-time ally President Bashar al-Assad, enabling him to win back swathes of territory from IS and rebel groups.

Washington and Moscow arranged a ceasefire in February between Assad and the rebels which left them both free to continue attacks on IS.

Stoltenberg had said in January a meeting of the NATO-Russia Council was under consideration, stressing the need to avoid misunderstandings after the November shooting down of a Russian fighter jet by key alliance member Turkey along its border with Syria.

Diplomatic sources said at the time the idea was to hold a series of council meetings in the run-up to NATO's July summit in Warsaw which has led calls for a more forceful response to Russia over Ukraine.