NATO is discussing whether to invite Russia to their first formal talks since 2014, aiming to put ties damaged by the Ukraine crisis back on an even keel, diplomatic sources said Wednesday.

Despite their differences both sides recognised the need for "transparency", the sources said, against a backdrop of a series of crises including Ukraine and the war in Syria.

"The meeting will not take place before the NATO defence ministers meeting (on February 10-11) but it is likely at the end of February or early March," one of the sources told AFP.

"We still have to talk to Russia about it and what the agenda might be. Ukraine of course will be on the list but we will have to see what else there is," the source said, asking not to be identified.

The US-led alliance suspended all practical cooperation with Russia after its intervention in Ukraine and 2014 annexation of Crimea, but decided to leave what is known as the NATO-Russia Council (NRC) in place.

The NRC groups all 28 NATO member states, usually at ambassador level with their Russian counterpart, to manage ties but it has been in limbo since a last, frosty meeting in June 2014.

Germany especially has pressed for an opening to Moscow as the West looks to Russia for help on key issues such as Syria and the threat from the Islamic State group.

The sources said the aim now was to hold a series of NRC meetings in the run-up to a NATO leaders summit in Warsaw in July which will endorse the broad readiness upgrade they approved to counter a more assertive Russia.

The sources stressed that resuming contact with Russia in the NRC was not meant to signal any softening in NATO's stance but rather to better manage what is likely to be a difficult relationship for years to come.

"The aim of this new dialogue is two-fold -- deterrence and transparency," one of the sources said.

"We are ready to talk so that the situation does not degenerate ... we know that we face years, even decades of tensions with Russia and so this would acknowledge that fact and that we have to find a modus vivendi," the source said.

NATO officials declined to comment directly on the possibility of an NRC meeting but recalled that the forum had not been suspended.

They also noted that NATO head Jens Stoltenberg had said in December that the alliance was "looking into how we can use a tool which has been there all the time."

Stoltenberg has separately met Russian Foreign Minister Sergei Lavrov several times since relations between Russia and the West soured.