Ukrainian police have clashed with anti-government protesters at Kyiv's city hall in an effort to drive the activists from the building.
Reports from the Ukrainian capital say the protesters fought back by spraying water from fire hoses at the baton-wielding police.
The clash came just hours after hundreds of Ukrainian police began storming a protest encampment in central Kyiv early Wednesday, clashing with the demonstrators and ripping down their makeshift tent city.
The U.S. State Department issued a statement expressing "disgust" with the actions of Ukrainian authorities for introducing bulldozers and riot police armed with batons to the scene, rather than, in the words of Secretary of State John Kerry, "respect for democratic rights and human dignity."
Kerry said that "respect for democratic principles, including freedom of assembly" is fundamental to the United States' approach to Ukraine. He said these values are universal, not just American. He called for "utmost restraint" and said human life must be protected.
U.S. Assistant Secretary of State Victoria Nuland met with Ukrainian President Viktor Yanukovych Wednesday and told reporters afterwards that she told him such clashes were unacceptable.
"I made it absolutely clear to him that what happened last night, what has been happening in security terms here, is absolutely impermissible in a European state, in a democratic state," Nuland told reporters.
WATCH - Remarks by U.S. Assistant Secretary of State Victoria Nuland in Ukraine:
Nuland expressed optimism that a solution was close at hand, telling reporters that Yanukovych "knows what he needs to do."
Also Wednesday, Nuland handed out sandwiches to both protestors and police in Kiev's Independence Square following the overnight face-off between protesters and riot police.
On Tuesday, European Union foreign policy chief Catherine Ashton and U.S. Assistant Secretary of State Victoria Nuland met in the capital with senior government and opposition leaders in a push to ease the crisis. Later, Ashton walked through the square to view the protests and speak with reporters.
Earlier Tuesday, Ukrainian President Viktor Yanukovych met with three former Ukrainian presidents, launching so-called round table talks reportedly aimed at the same objective.
The protests began in late November, after the Ukrainian president backed away from a long-anticipated trade deal with the European Union, in favor of repairing and improving economic and political ties with Russia.
In a nationally televised address Tuesday following his meeting with his predecessors, Mr. Yanukovych called for the release of protesters arrested after a violent police crackdown November 30. He said good relations with both Russia and the European Union are necessary to protect the country's interests.
Moscow is seeking to form a trade bloc of former Soviet republics and satellite countries to rival the European Union, and has in recent months exerted strong economic pressure on its impoverished neighbor to scuttle the EU deal.
Earlier this year, it imposed restrictions on goods from Ukraine, cutting Ukrainian exports by 25 percent and dragging the country into recession.
Russia is Ukraine's largest foreign investor, trading partner and chief natural gas supplier. Moscow is reported to be dangling a deal with Ukraine that includes a $9 billion annual discount on gas pipeline shipments.
Analysts say Kyiv, which has also secured recent investment deals with China, still needs about $18 billion in outside help to pay government debt and meet energy payments to Russia by early 2014.