The White House on Thursday called on Ukrainian President Viktor Yanukovych to withdraw security forces from downtown Kiev after renewed violence put an end to a brief truce between his government and opposition forces.

“We are outraged by the Images of Ukrainian security forces firing automatic weapons on their own people,” White House press secretary Jay Carney said. “We urge President Yanukovych to immediately withdraw his security forces from downtown Kiev and to respect the right of peaceful protest, and we urge protesters to express themselves peacefully. “

On Wednesday, the Ukranian government and protesters declared a truce. Just hours later, though, violent clashes between police and the opposition brought the death toll this week up to 50 people.

Yanukovych on Thursday claimed police were unarmed and that "all measures to stop bloodshed and confrontation are being taken."

The White House, however, said the Ukrainian leader was inciting the violence in his country.

“The use of force will not resolve the crisis -- clear steps must be taken to stop the violence and initiate meaningful dialogue that reduces tension and addresses the grievances of the Ukrainian people,” Carney said. “The United States will work with our European allies to hold those responsible for violence accountable and to help the Ukrainian people get a unified and independent Ukraine back on the path to a better future.”

The conflict in Ukraine has set up another proxy showdown between the United States and Russian President Vladimir Putin, who has propped up the Yanukovych regime.

Putin has accused the U.S. and Western powers of meddling in Ukrainian affairs, saying threats of sanctions against the country amounted to blackmail.

For his part, President Obama tried to shy away from another spat with Russia.

“Our view is not to see it as some Cold War chessboard where we are in competition with Russia," Obama said late Wednesday during a press conference in Mexico.