Russia has again bolstered its troops presence on its frontier with Ukraine’s east, triggering concerns of cross-border fire or a possible intervention in support of pro-Moscow rebels increasingly besieged by Ukrainian government forces.
The spike in troop and military hardware levels has been confirmed by both NATO and US military officials.
"In early August, Russia significantly increased the number of troops in the vicinity of the Russian border. Our current assessment is that around 20,000 troops are now in the area. This troop presence includes tanks, infantry, artillery, air defense systems, as well as logistics troops, special forces, and various aircraft," a NATO official said in a written statement.
A spokesman for Ukraine's National Security and Defense Council, Andriy Lysenko, said Tuesday that Russia has deployed 45,000 troops to the border - along with a large number of tanks, artillery, multiple rocket launchers and aircraft.
He also said that Russian forces fired artillery and Grad rockets at Ukrainian positions across the border for several hours on Monday.
In addition, Moscow has announced a five-day drill inside Russian territory, involving some 100 warplanes, helicopters and anti-aircraft batteries. Some of the exercises are being conducted close to Russia’s border with Ukraine.
With Ukrainian troops advancing toward the two remaining rebel strongholds of Donetsk and Luhansk, officials in Kyiv have expressed concern over a possible Russian offensive. Short of a full-blown military incursion, Russia might also be considering sending its forces as “peacekeepers” into eastern Ukraine, officials in Kyiv say.
Ukrainian government troops have been steadily gaining ground since the country elected a new president in late May.
Putin on sanctions
Meanwhile, Russian President Vladimir Putin says he has ordered his Cabinet to prepare a response to Western sanctions.
During a meeting with Alexei Gordeyev, the governor of the Voronezh region near Ukraine, Putin said the use of "political instruments of pressure" against Russia's economy are "unacceptable" and contradict "all norms and rules." He said, however, that any retaliatory measures in response to the sanctions must be taken "very carefully," to support domestic producers without harming consumers.
The United States and its allies have imposed several rounds of sanctions on Russia for its annexation of Ukraine's Crimean peninsula from Ukraine and support of the separatists in eastern Ukraine.
Meanwhile, a leading human rights group has accused pro-Russia rebels in Ukraine’s east of aggravating the humanitarian crisis triggered by the four-month-old conflict.
U.S.-based Human Rights Watch issued a statement Tuesday saying rebel attacks on medical personnel and facilities have "compromised the ability of civilian patients to receive treatment." The group says separatist forces have stolen and destroyed medical equipment and hospital furniture, and hijacked ambulances and used them to transport their fighters.
Human Rights Watch also says at least two medical workers have been killed in mortar attacks that were likely carried out by Ukrainian forces.
Ukraine’s Defense and Security Council spokesman Andriy Lysenko told reporters Monday the military has opened humanitarian corridors for Donetsk residents to flee a planned government offensive, and that steps are being taken to assist evacuees find temporary shelter.
Ukraine, Washington and its European allies accuse Moscow of arming rebels and having provided them with the missile battery used to bring down a Malaysian airliner last month.
Both Russia and the rebels in Ukraine have denied involvement.
The jetliner with 298 people on board was downed July 17 near Donetsk. There were no survivors.
Search teams on Monday continued their efforts to locate remains of more victims from Malaysia Airlines Flight 17, most of whom where Dutch nationals.
The head of the Dutch police mission working at the crash site says crews have finished searching one of five zones of the site. He said completing the search will take at least three weeks.
VOA's Jeff Seldin has contributed to this report from the Pentagon; additional information provided by Reuters.