Petro Nazapo sharpens a wooden table leg with his penknife as he prepares for another night at the barricade of sandbags and barbed wire.

"We're preparing for another attack," said the helmeted, middle-aged protester from Lviv in western Ukraine, who has manned this post every night for the past month.

Ukraine's parliament on Friday overwhelmingly backed a law that could pave the way for the quick release of jailed opposition leader and former premier Yulia Tymosehnko.

A total of 310 deputies in the 450-seat Verkhovna Rada voted to decriminalize the "abuse of power" statute under which Tymoshenko was jailed for seven years in 2010. The measure must still be signed by Ukraine's president to enter into force.

U.N. chief Ban Ki-moon called Ukrainian President Viktor Yanukovych on Friday, urging him to quickly and fully implement a deal ending the country's worst crisis since independence, a spokesman said.

Ukraine's leader and opposition on Friday signed the deal after three days of carnage left nearly 100 protesters dead.

European Union president Herman van Rompuy welcomed an agreement signed Friday by Ukraine's leader and the opposition to end a deadly standoff but said it must be followed by concrete action.

"The agreement is a necessary compromise in order to launch an indispensable political dialogue that offers the only democratic and peaceful way out of the crisis that has already caused too much suffering and bloodshed on all sides," he said in a statement. "It is now the responsibility of all parties to be courageous and turn words into deeds for the sake of Ukraine's future."

Talks led by three EU ministers on the future of Ukraine have stopped the immediate bloodshed, but an agreement remains "far off", Poland's prime minister said Friday.

"For now, this objective (to end bloodshed) has been achieved, but the road to an agreement is still very far off," Prime Minister Donald Tusk told reporters in Warsaw.

Ukraine's embattled leader signed a deal Friday with the opposition in a bid to end the ex-Soviet country's worst crisis since independence after three days of carnage left nearly 100 protesters dead.

But President Viktor Yanukovych's dramatic decision to hold early elections and form a new unity government while granting amnesty for those involved in the violence was met with skepticism or even hostility by nearly 40,000 protesters who gathered on central Kiev's main square -- many of them frustrated the leader was not stepping down.

"The downgrade reflects our view that the political situation in Ukraine has deteriorated substantially," the agency said in a note a day after the deadliest day in the ex-Soviet country's three-month-old political crisis left more than 60 anti-government protesters shot dead.

"We believe that this raises uncertainty regarding the continued provision of Russian financial support over the course of 2014, and puts the government's capability to meet debt service at increasing risk," it said.

Vice President Joe Biden on Thursday warned Ukrainian President Viktor Yanukovych that the United States was ready to impose sanctions on officials guilty of ordering troops to fire on protesters.

Biden spoke to the Ukrainian leader by telephone and "made clear that the United States is prepared to sanction those officials responsible for the violence," the White House said in a statement.

A 21-year-old volunteer medic who tweeted "I am dying" after she was reportedly shot in the neck during violent protests in the Ukrainian capital Thursday sparked an outpouring of sadness online.

Olesya Zhukovska posted the words in Ukrainian on her Twitter feed and Facebook-like VKontakte account Thursday afternoon, adding fuel to an already emotionally-charged situation after fierce clashes between protesters and riot police on Kiev's central Independence Square claimed dozens of lives.

German Chancellor Angela Merkel and U.S. President Barack Obama joined with Russian President Vladimir Putin on Thursday to call for an urgent political solution to the deadly crisis gripping Ukraine.

"The chancellor and the presidents have reached an agreement to call for a political solution to the crisis in Ukraine as quickly as possible and for an end to the bloodbath," the German government said in a statement released after phone calls between the Western leaders and Putin, who have been at odds over Ukraine's future.