German Chancellor Angela Merkel urged President Vladimir Putin on Wednesday to push for a "constructive dialogue" to defuse the crisis in Ukraine, her office said.

Merkel held telephone talks with the Russian leader asking him to "push at his end for a constructive dialogue between the opposition and government" in Ukraine, it said in a statement.

EU foreign policy chief Catherine Ashton on Wednesday called for an end to the "violence and intimidation" in Ukraine, saying there needed to be a real dialogue between the authorities and the opposition.

"The violence and intimidation, wherever it comes from, must be stopped," she told reporters in Kiev following a meeting with President Viktor Yanukovych. "The dialogue that has happened from time to time (between the opposition and authorities) needs to be a real dialogue," she added.

Ukraine's embattled President Viktor Yanukovych is determined to hold on to power and will likely use force or illegal steps to counter popular protests, the U.S. intelligence chief said Wednesday.

"Firmly intent on maintaining his hold on power, Yanukovych will probably resort to coercion, extralegal means, and other tactics to tilt the playing field in his favor and ensure his reelection, threatening a further erosion of democratic norms," National Intelligence Director James Clapper said in a written statement to senators.

Activists from a radical Ukrainian protest group on Wednesday vacated the agriculture ministry they had occupied for five days after clashes with other opposition protesters who demanded that they leave.

The Spilna Sprava (Common Cause) activists walked out of the agriculture ministry building after representatives of the more mainstream opposition urged them to leave it so as not to impede negotiations with the authorities about an amnesty, an Agence France Presse correspondent said.

Ukraine's parliament on Wednesday launched a debate on whether to grant amnesty for detained protesters as the country's first post-independence president warned of civil war.

A day after scrapping tough anti-protest laws that had ignited the latest political turmoil, deputies met in an extraordinary session to consider granting amnesty to those arrested in the anti-government unrest.

For every Ukraine protester smashing in a window, throwing a Molotov cocktail or being hit by riot police, there will be several people standing nearby with their smartphones aloft livestreaming the event.

Web channels have sprung up -- some with presenters in improvised studios commenting in real time on the live feeds from protests in Kiev and beyond -- and clips of some of the most shocking clashes have gone viral on social media.

Canada will refuse entry to any Ukraine government officials linked to a crackdown on protestors, the immigration minister announced Tuesday, while condemning violence there.

"Effective immediately, our government will be restricting the entry to Canada of key officials of the Ukrainian government who are responsible for the oppression of citizens and the opposition as they defiantly and courageously speak out in support of freedom and democracy," the minister, Chris Alexander, told reporters.

President Vladimir Putin pledged Tuesday that Russia would maintain a $15 billion loan and cuts on energy prices to Ukraine even if the opposition came to power.

"In direct answer to your question as to whether we will review our agreements on loans and energy if the opposition comes to power - no we will not," Putin told a news conference at the close of talks in Brussels with the European Union's top officials.

Ukraine's prime minister and entire government resigned on Tuesday and its parliament scrapped anti-protest laws that had infuriated the opposition, in the biggest concessions yet to protesters in a two-month crisis.

Ukraine also dominated an EU-Russia summit in Brussels at which Russian President Vladimir Putin struck a conciliatory tone, saying he would not revise the terms of a bailout for Kiev even if the opposition came to power.

U.S. Vice President Joe Biden urged Ukrainian President Viktor Yanukovych Monday to pull back riot police and work with the opposition on "immediate measures" to de-escalate tensions between the government and protesters.

In a phone call, Biden -- "underscoring that no time should be lost" -- also warned that "declaring a state of emergency or enacting other harsh security measures would further inflame the situation and close the space for a peaceful resolution," according to a White House statement.