U.S. Vice President Joe Biden on Tuesday met Didier Burkhalter, leader of Switzerland and current head of the OSCE group that is seeking a leading role during Ukraine's political transition.

Biden held nine phone calls with ousted Ukrainian leader Viktor Yanukovych in recent weeks, seeking to quell political violence, and has emerged as the White House's top pointman on the issue.

The United States and Britain on Tuesday voiced support for Ukraine amid its political turmoil, vowing it should not be seen as a battleground between East and West.

British Foreign Secretary William Hague after talks with his American counterpart John Kerry also backed Ukraine's territorial integrity, amid fears that the nation with strong links to Russia could be torn apart by the upheaval.

The main cleric in Ukraine's Greek Catholic Church on Tuesday warned about the risks of civil war and separatism in his homeland during a visit to Rome.

The Major Archbishop of Kyiv-Halych, Sviatoslav Shevchuk, also appealed for the European Union to offer "economic aid and above all diplomatic support".

A thin wisp of smoke rises from a chimney in the barricaded residential complex of deposed president Viktor Yanukovych in the eastern city of Donetsk, but Ukraine's most famous fugitive is nowhere to be seen.

The mystery of the former president's whereabouts has gripped the nation since he fled the capital on Friday, following a week of deadly clashes between anti-Yanukovych protesters and security forces. Many believe he is holed up somewhere in the Russophone east of the country.

Ukraine's parliament on Tuesday called on the International Criminal Court in the Hague to prosecute ousted president Viktor Yanukovych over the "mass murder" of protesters in Kiev.

"We appeal to the International Criminal Court...to bring to justice Viktor Yanukovych and other high-ranking figures who gave and carried out criminal orders," the parliament said in a statement.

Moscow pledged Tuesday it would not intervene in the crisis in neighboring Ukraine but said the country should not be forced to choose between Russia and the West.

"We confirmed our principled position of non-intervention in Ukraine's internal affairs and expect that everyone follows similar logic," Foreign Minister Sergei Lavrov said.

Ukraine's interim leader on Tuesday delayed the appointment of a new unity government until Thursday as the country struggled to find a way out of its most serious crisis since independence.

"On Thursday a coalition of national faith must be elected," interim president Oleksandr Turchynov told legislators in parliament, where a new cabinet and prime minister had been due to be unveiled on Tuesday.

More than 400 Russian protesters faced court hearings on Tuesday a day after police detained them at a central Moscow rally, the largest such wave of arrests in nearly two years.

The demonstrators had gathered near Red Square late on Monday in support of activists jailed earlier in the day for staging "mass riots" in May 2012, a key case seen as a symbol of the harsh crackdown on dissent under President Vladimir Putin's latest term.

To some he is "a traitor", to others he is "too weak". But residents of Viktor Yanukovych's home town in Ukraine's Russian-speaking east have no regrets over his downfall.

Ousted by parliament, rejected by his own party and wanted for "mass murder", Ukraine's former president has been abandoned by his erstwhile electoral heartland of Donetsk, the industrial city where he was born in 1950.

The United States Monday stopped short of fully endorsing Ukraine's interim leader Oleksandr Turchynov as its legitimate ruler, but called for a technocratic government in Kiev to promote early elections.

White House spokesman Jay Carney noted that President Viktor Yanukovych was "not actively leading the country at present" and that Washington could not confirm where he was.