Russia and the United States have both suspended their participation in the Intermediate-Range Nuclear Forces (INF), accusing each other of violating the accord, which banned a whole class of nuclear-capable missiles.

Washington will definitively quit the deal on August 2 unless Russia destroys a controversial new missile system the US and NATO say breaches the accord, signed in 1987 between US president Ronald Reagan and Soviet leader Mikhail Gorbachev.

NATO held talks with senior Russian officials as part of efforts to save the deal, a week after alliance defence ministers agreed a package of counter-measures in case Moscow ignores the deadline.

"We didn't see any sign of Russia being willing to come back into compliance with the INF treaty," Stoltenberg told reporters after the meeting, adding that the "ongoing Russian violation" was the only reason the treaty was under threat.

He said there was still time to save it, pointing to the speed with which Soviet forces were able to get rid of their medium-range weapons after the INF was signed.

"Back in 1987 Russia was able to destroy intermediate range cruise missiles in a few weeks," he said.

"It is possible to do it in a few weeks because that has happened before."

The INF, which banned ground-launched missiles with a range of 500 to 5,500 kilometres (310 to 3,400 miles), is seen as a cornerstone of the global arms control architecture and its looming demise has triggered fears for the future of the New START treaty, which caps nuclear warhead numbers.

Alliance ministers last week agreed to review air and missile defences, along with intelligence and surveillance programmes, to boost their readiness to deal with the threat posed by Russia's new 9M729 ground-launched cruise missiles.

Stoltenberg refused to give further details of the measures on Friday, saying NATO was still focused on trying to save the deal, but he said the alliance's existing ballistic missile defence shield would not be capable of shooting down Russian missiles.