U.S.: Russia breaking Ukraine truce with troop buildup

WASHINGTON, April 23 (UPI) -- Russia is increasing air defense systems and troop concentrations within eastern Ukraine, each a truce violation, the U.S. State Department said.

"The Russian military has deployed additional air defense systems into eastern Ukraine and moved several of these nearer the front lines. Russia is also building up its forces along its border with Ukraine. After maintaining a relatively steady presence along the border, Russia is sending additional units there," State Department spokeswoman Marie Harf said in a statement. The buildup contravenes a truce signed in Minsk in February.

"Combined Russian-separatist forces maintain a sizable number of artillery pieces and multiple rocket launchers within areas prohibited under the Minsk accords. The Russian military has deployed additional air defense systems into eastern Ukraine and moved several of these nearer the front lines."

Russia now has its strongest military presence within and along the Ukrainian border since October 2014, an increase in tension after a two-month lull in fighting in eastern Ukraine.

Russian troops have also been involved in training with pro-separatist rebels, including on the use of drones, an unmistakable sign of a Russian presence, the State Department said. A focus of the troop buildups are the cities of Mariupol and Kharkiv;

Mariupol, a port city, was seized by separatists last summer and retaken by Ukrainian troops, and lies on a strategic highway to Crimea, which was annexed by Russia in 2014. Kharkiv has remained under control of Kiev, and the massing of troops near the two cities suggests each could be vulnerable to a simultaneous attack.

Russia has repeatedly denied sending troops or weapons to Ukraine.