The US has accused Russia of building up its largest military presence along its border with Ukraine since October 2014. Air defense systems have also been deployed, the US says.
The United States accused Russia on Wednesday of building up its forces along the border with Ukraine, boosting air defense systems and training Ukrainian separatist rebels in the east.
Some 300 US paratroopers this week began training about 900 Ukrainian National Guard troops (photo), bringing sharp criticism from Moscow.
Russia was adding forces to create what would be its "largest presence on the border since October 2014," acting State Department spokeswoman Marie Harf said in a statement.
Harf added that "combined Russian-separatist forces continue to violate the terms of the 'Minsk 2' agreement signed in mid-February."
Observers with the Organization for Security and Co-operation in Europe (OSCE) have reported heavy arms fire by both the Ukrainian army and pro-Russian separatist fighters in recent weeks. Both sides signed a ceasefire agreement in February in the Belarus capital, Minsk.
Harf said that Russian and rebel forces had "a sizable number of artillery pieces and multiple rocket launchers within areas" banned under the ceasefire. They were continuing to ship heavy weapons into Ukraine, she added.
The Russian military had also "deployed additional air defense systems into eastern Ukraine and moved several of these nearer the front lines. This is the highest amount of Russian air defense equipment in eastern Ukraine since August," Harf said.
The State Department spokeswoman accused Russia of "conducting increasingly complex training" inside eastern Ukraine. They were also using drones, she said: "an unmistakable sign of Russia's presence."
The United Nations says more than 6,000 people have been killed in the Ukrainian conflict in the past year and more than a million civilians have been displaced.
jm/bk (AFP, dpa)