Russia's President Vladimir Putin delivers a speech during a session of the Valdai Discussion Club in Sochi, Russia October 19, 2017. REUTERS/Alexander Zemlianichenko/Pool

SOCHI, Russia (Reuters) - Russia will respond immediately and symmetrically if the United States quits the intermediate-range nuclear forces treaty, Russian President Vladimir Putin said on Thursday.

Moscow is ready to develop new weapons systems, both nuclear and non-nuclear, in response to other countries doing the same, Putin said at a forum with scholars.