The Kremlin said on Monday that Russia would be forced to respond in kind if the United States began developing new missiles after quitting a landmark Cold War-era treaty. President Donald Trump said on Saturday that Washington would withdraw from the Intermediate-Range Nuclear Forces Treaty because Russia was violating the pact, triggering a warning of retaliatory measures from Moscow. Kremlin spokesman Dmitry Peskov told reporters on Monday that the U.S. move would make the world a more dangerous place and said Russia would be forced to act to restore the balance of military power if Washington quit and started developing new missiles.