NATO Secretary General Jens Stoltenberg speaks during a media conference at NATO headquarters in Brussels. Picture: Virginia Mayo/AP

Brussels - NATO defence ministers are due Wednesday to prepare for the expected demise of a Russia-US nuclear non-proliferation deal that has been a cornerstone of Europe's security architecture for the past three decades.

The Intermediate-Range Nuclear Forces (INF) Treaty, signed by the United States and the Soviet Union in 1987, bans ground-launched missiles capable of carrying a nuclear warhead a distance of 500 to 5,500 kilometres.

Washington, backed by its NATO allies, accuses Moscow of being in breach of the deal by developing its 9M729 missile system, known to NATO as SSC-8. It has set an August 2 deadline for Russia to comply, or else the treaty will expire.

Russia rejects the accusation and has announced its intention to pull out of the deal.

Efforts are still focused on bringing Russia into compliance, NATO Secretary General Jens Stoltenberg said on Tuesday, noting that the window of opportunity is getting "smaller and smaller."

However, NATO defence ministers meeting in Brussels for two-day talks will prepare various possible steps to be taken if, as expected, Russia remains in breach.

NATO's response will be "defensive, measured and coordinated," Stoltenberg said ahead of the meeting. There are no intentions to deploy new land-based nuclear missiles in Europe, he added.

"All options are on the table," US ambassador to NATO Kay Bailey Hutchison said in a separate Tuesday briefing.

Ministers are also expected to adopt NATO's first ever space policy, discuss efforts to meet defence expenditure targets and hold talks on new technological challenges.

Recent tensions between Iran and the US are likely to be addressed on the sidelines.