Representatives of the presidential and government administration are reportedly discussing the imposition of a state of emergency.

According to an unnamed government source, as cited by the RBK-Ukraine news agency, discussions are underway on whether to declare a state of emergency on Monday.

According to TV channel TBi, the talks are taking place in the Mezhigorye residence and hundreds of protesters have headed to the site by car in a bid to stage a blockade.

Local police are said to have taken steps to strengthen security in the region.

A state of emergency over the entire territory of Ukraine or over parts of the country can be imposed through a presidential decree.

The decree is to be approved by the Verkhovna Rada within 48 hours after the address to the nation.

On Sunday, hundreds of thousands of Ukrainians took to the streets of Kiev to vent their anger over the president's refusal to sign a strategic trade agreement with the European Union and seek to strengthen ties with Russia instead.

There were clashes in front of the presidential office as demonstrators tried to use an excavator to break through police lines, while security forces responded with tear gas and flash grenades.

Sunday's rally, held despite a ban on rallies in key locations in Kiev's city center until January 7, was driven by opposition to the violent dispersal by riot police of a protest on Saturday of pro-EU activists against the decision of President Viktor Yanukovich to back out of a crucial EU integration agreement.