KIEV, Jan. 27 – President Viktor Yanukovych held fresh talks with opposition leaders on Monday to prepare for a crunch session of Parliament at which the president and his allies will be under pressure to make major concessions amid mass unrest.

A tough battle lay ahead at Tuesday's session, with the opposition calling for concessions including the repeal of sweeping anti-protest laws, the dismissal of the government and an amnesty for all protesters detained in two months of unrest, Reuters reported.

Ukraine's justice minister raised tensions by warning she would press for a state of emergency if protesters did not vacate a ministry building they had occupied overnight.

The protesters later left the premises, after defying police for several hours, but said they would return if there was no progress in parliament on Tuesday.

US Vice-President Joe Biden spoke by telephone to President Yanukovych late on Monday to express Washington's support for on-going negotiation to bring about a peaceful, political solution to the crisis, BBC reported.

He warned that enacting other harsh security measures would further inflame the situation and close the space for a peaceful resolution, a White House statement said.

The law angered protesters and helped to spread unrest across Ukraine, even to Yanukovych's Russian-speaking strongholds in the east.

The protesters, closely allied to the opposition parties, targeted government buildings and have briefly occupied several ministries in Kiev.

As the opposition leaders - Vitaliy Klitschko, Arseniy Yatseniuk and Oleh Tiahnibok - met Yanukovych, the President's party set the scene for a rowdy session of parliament, saying they did not intend to yield any ground.

"The prime minister will not be going. Parliament tomorrow will not be voting for the resignation of the government," Mykhailo Chechetov, a spokesman for the Party of the regions, told Interfax news agency.

He said the Regions parliamentary faction would equally block any attempt to repeal the anti-protest legislation which Yanukovych loyalists rammed through parliament on January 16.

"We are categorically against changing these laws. What are we talking about here? A bandit must go to jail," he said.

The Batkivshchyna party of jailed opposition leader Yulia Tymoshenko, now headed by Yatseniuk, called on its supporters to rally in Kiev's Independence Square on Tuesday in solidarity with opposition deputies in parliament.

"Come at 12 o'clock and support the deputies who are ready to take on themselves the responsibility for getting rid of these dictatorial laws," a statement said.

A State of Emergency would limit movements of people and vehicles, ban rallies, marches and strikes, suspend the activity of political parties and introduce a curfew.

The unrest has spilled over into other regions of the country of 46 million people, including areas of eastern Ukraine and the south which are traditionally pro-Yanukovych. (rt/ez)