WASHINGTON, April 28 – More Russian air defense systems have been deployed in eastern Ukraine, reaching the highest number recorded since August 2014, the U.S. Department of State said.

"Russian and separatist forces maintain a sizable number of artillery pieces and multiple rocket launchers within areas prohibited under the Minsk agreements. Also, the Russian military has deployed additional air defense systems into eastern Ukraine and moved several of these nearer the front lines," Acting Deputy Spokesperson of the U.S. Department of State Jeff Rathke said.