The United States has said Russia has been breaching the Minsk ceasefire in eastern Ukraine by boosting its military presence and training pro-Russian separatist rebels in the region.
Speaking from Washington Wednesday, US State Department spokeswoman Marie Harf accused Russia of building up its air defense equipment in rebel-held areas, including the usage of Russian unmanned aerial vehicles.
The training exercises "leave no doubt that Russia is involved," Harf said, noting the highest level of Russian activity in the region since October.
"The training has also incorporated, an unmistakable sign of Russian presence," the spokeswoman added.
"After maintaining a relatively steady presence along the border, Russia is sending additional units there."
If the US claims are true, Russia’s movement of heavy arms to the border will be counted as a violation of the Minsk 2 agreement which was signed in the Belarus capital on Feb. 15.
“Combined Russian-separatist forces maintain a sizable number of artillery pieces and multiple rocket launchers within areas prohibited under the Minsk accords,” Harf said.
Speaking to the New York Times, one unidentified Western official said Russia had moved 12 battalion tactical groups close to the border.
The ceasefire between the pro-Russian rebels and the Ukrainian army has proved to be highly fraught, with observers from the Organization for Security and Co-operation in Europe (OSCE) have recording a number of incidents including heavy arms fire in recent weeks.
Russia’s Kremlin spokesman Dmitry Peskov previously warned that the sending of 300 American paratroopers to train Ukrainian national guard units to help them in the fight against the rebels in eastern Ukraine “could seriously destabilise the situation.”
At least 6,116 people have been killed since fighting broke out in the region last year, following the ousting of pro-Russian leader Viktor Yanukovych, who fled the country following pro-EU protests in Kiev.
The crisis led to the autonomous government in Crimea, which is dominated by ethnic Russians, to declare independence from Ukraine and eventually be annexed by Russia following a referendum.
Western nations punished Russia for the annexation by enforcing crippling economic sanctions, which have put the country into recession and led to the devaluation of its rouble currency.
The sanctions, however, may be lifted if Russia sticks to its side of the Minsk 2 agreement.