Russia said on Wednesday it would not let the United States inspect a new nuclear-capable cruise missile at the heart of a dispute between Washington and Moscow that risks unraveling a landmark arms control treaty.

Washington has threatened to pull out of the 1987 Intermediate-range Nuclear Forces Treaty (INF), alleging that the new Russian missile, the Novator 9M729 (called SSC-8 by NATO), violates the pact, which bans either side from stationing short and intermediate-range, land-based missiles in Europe.

Russia says the missile's range puts it outside the treaty altogether and is not as long as Washington alleges, meaning that it is fully compliant with the INF. It has accused the United States of inventing a false pretext to exit a treaty it wants to leave anyway so as to develop new missiles.