The U.S. special envoy for Ukraine peace negotiations said the ex-Soviet country is locked in a "hot war" with Russia-backed separatists and pinned the blame on Moscow for the conflict.
Kurt Volker, who was recently appointed as Washington's point man for talks on ending the conflict between Kyiv's forces and the separatists, delivered the assessment during a July 23 visit to Ukraine's war-torn east.
"This is not a frozen conflict, this is a hot war, and it's an immediate crisis that we all need to address as quickly as possible," Volker told reporters at a news conference in Kramatorsk, the headquarters of Kyiv's military operation against the separatists.
Asked later during the news conference whether the United States understood that Russian "aggression" was to blame for the situation and not a "civil war," Volker answered in the affirmative.
"We've seen what's happened, we understand the way this conflict has begun, we understand the way it is being managed today, and that's why it's important that the United States become more engaged," Volker, a former U.S. ambassador to NATO, said.
Volker was appointed in early July as Washington's special representative on negotiations to bring an end to the conflict, which has killed more than 10,000 since April 2014.
Kyiv, the United States, the EU, and NATO accuse Russia of backing the separatists with weapons and personnel. Moscow rejects the accusation despite substantial evidence of such support.
A cease-fire deal signed in February 2015 in the Belarusian capital, Minsk, has failed to end the violence, which has recently flared up and led to the killing of several Ukrainian soldiers in recent days.
Asked if he plans to visit the other side of the front line, Volker told locals and the media on July 23 that he plans "to meet a Russian counterpart at some point."
"I think that meeting with the Russians is what we need to do in order to gain the perspective -- the strategic perspective -- over how to resolve this," he said.
In video released by the Ukrainian military on July 23, Volker was shown arriving by helicopter at its operations in the east and speaking with military officials there.
The U.S. State Department said on July 21 that during his visit to eastern Ukraine, Volker would "meet with those who have been affected by Russian aggression" and "discuss the importance of security and safety for all Ukrainians."
He was set to meet Ukrainian officials in Kyiv on July 24 "to discuss the path to restoring Ukraine's sovereignty and territorial integrity," the State Department said.
Despite U.S. President Donald Trump's stated desire to improve ties with Moscow, his administration has maintained the punitive measures targeting Russia for its actions in Ukraine that began under Trump's predecessor, Barack Obama.
The Obama administration hit Russia with several waves of sanctions over its seizure of Ukraine's Crimean Peninsula and subsequent backing of the separatists.
Republican and Democratic lawmakers in Washington, meanwhile, say they have reached agreement on legislation that would allow new sanctions targeting Moscow -- as well as Iran and North Korea -- and would limit any possible effort by Trump to ease sanctions against Russia.
The Republican-led House of Representatives is set to vote on the bill as early as July 25. The legislation would require the White House to obtain permission from Congress before easing or lifting sanctions against Russia.
With reporting by RFE/RL's Christopher Miller, Reuters, and AP