Russia has suspended its involvement in the Intermediate-Range Nuclear Forces Treaty (INF), a day after the US made a similar announcement.
Washington has accused Moscow of repeatedly violating the terms of the pact.
The Trump administration said they will serve formal notice and withdraw altogether in six months.
From Washington, our correspondent Daniel Ryntjes reports.
US withdraws from INF treaty
Meanwhile, Russia's President Vladimir Putin said the country plans to start work on creating new missiles, and ministers should not initiate disarmament talks with the US.