The U.S. said last week it would stop abiding by the Cold War treaty banning intermediate-range nuclear missiles. "Our response will be symmetrical," Russian President Vladimir Putin said.
The president cited Russian aggression against Ukraine in his tweet about the change. He still has a series of meetings planned on the sidelines of the summit, including with China's Xi Jinping.
The U.S. imposed sanctions after China's military bought new fighter jets and a surface-to-air missile system. Trade and military ties are increasing between Russia and China.
Russia's president said the men whom U.K. police recently accused of poisoning former spy Sergei Skripal are private citizens, not Russian agents, and urged them to speak out.
The Pennsylvania congressman served in the FBI and says he has full confidence in the U.S. intelligence community. Days ago, GOP Rep. Will Hurd of Texas came to the same conclusion.
The U.S. and Russia still inspect each other's nuclear arsenals and have sharply curtailed the number of weapons poised to launch. That's thanks to two arms control treaties, which are now at risk.
Trump repeatedly offered support to Russian leader Vladimir Putin and refused to endorse the U.S. intelligence community's finding that Russia interfered in the 2016 election to help Trump.
The Russian leader jumped behind the wheel of an orange dump truck, leading the charge across the 12-mile bridge connecting the two regions for the first time in history.