Days before the leaders of Russia and the U.S. hold a summit meeting in Alaska, Moscow’s forces breached Ukrainian lines in a series of infiltrations in the country’s industrial heartland of Donetsk.

U.S. President Donald Trump is meeting with Russian President Vladimir Putin in Alaska at a U.S. military base for a crucial summit.

"The key risk for Ukraine is that the Kremlin will try to turn certain local gains on the battlefield into strategic victories at the negotiating table," he said.