Washington (AFP) - Russian forces deployed near Ukraine's eastern border are "more lethal" than before and heavily armed with artillery and air defense weaponry, the Pentagon said Thursday.
"The force that we see arrayed on the border is exceptionally capable, probably more capable, more lethal than anything that we've seen up until now," spokesman Colonel Steven Warren told reporters.
The Russian contingent now had "higher concentrations" of field artillery, rockets, anti-aircraft systems, as well as engineers and other troops providing logistical and other support to combat forces, he said.
"It is a capable armed force that we are very concerned about," Warren said.
But the overall number of Russian troops along the Ukraine border had not increased and remained at roughly 10,000, he added.
His comments came as the conflict in Ukraine dominated a summit of NATO leaders in Britain, with calls for the alliance to offer more help to Kiev's military and to deploy troops in former Soviet bloc states that are now NATO members.
Ukraine's President Petro Poroshenko predicted a ceasefire deal would be agreed Friday that would end violence between his government and pro-Moscow separatists backed by Russia.
NATO has accused Moscow of sending hundreds of troops into Ukraine in what it calls the most serious threat to security in Europe since the Cold War.
NATO sees Russia's March annexation of Crimea from Ukraine as a violation of the 1997 NATO-Russia Founding Act which fixed Europe's post-Cold War borders and prohibited the use of force to change them.
Since the crisis erupted in March, the United States has provided about $70 million in "non-lethal" aid to Ukraine's security forces but it has so far opted against sending arms to Kiev.