BRUSSELS: The United States delivered Russia a 60-day ultimatum on Tuesday to come clean about what Washington says is a violation of a 1987 nuclear arms control treaty or it will be forced to start a six-month process of withdrawal.

U.S. Secretary of State Mike Pompeo said Russia had developed "multiple battalions of the SSC-8 missiles", referring to the land-based, intermediate-range Cruise missile which also has the name of Novator 9M729.

"Its range makes it a direct menace to Europe," he told a new conference after a meeting with his NATO counterparts.