U.S. Secretary of Defense Chuck Hagel, pictured on April 6, 2014. (UPI/Keizo Mori) | License Photo

WASHINGTON, April 29 (UPI) -- U.S. Secretary of Defense Chuck Hagel spoke by phone on Monday with Russian Defense Minister Sergei Shoigu regarding the situation in Ukraine.

According to Pentagon press secretary Rear Admiral John Kirby, the Russian defense minister reiterated his assurance that Russian forces would not invade Ukraine."


Hagel cautioned the leader of Russia's armed forces to "find a responsible way forward" and warned that "continued aggression would further isolate Russia and result in more diplomatic and economic pressure."