Ukraine's parliament has put off plans to vote on the formation of a national unity government until Thursday to allow consultations to continue.
"The vote on the national unity government should be on Thursday," Oleksander Turchinov, the speaker of the assembly and the acting president, told the chamber on Tuesday.
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The vote had been expected to take place during Tuesday's session; Turchinov had told members of parliament at the weekend that they had until Tuesday to form a new cabinet and appoint a new prime minister.
Until that happens, there can be no deals on international financial support, which the acting finance minister, Yuriy Kolobov estimated at $35bn for the next two years.
The announcement comes as the parliament also called on the International Criminal Court in the Hague to prosecute deposed President Viktor Yanukovich over the "mass murder" of protesters in Kiev.
"We appeal to the International Criminal Court...to bring to justice Viktor Yanukovich and other high-ranking figures who gave and carried out criminal orders," the parliament said in a statement.
Politicians have been trying to stabilise the country after the disappearance of Yanukovich and months of violence.
A presidential election campaign has already started with opposition leader Vitaly Klitschko announcing on Tuesday that he is running for president.
The Ukrainian Central Election Commission posted an election calendar online early on Tuesday, giving candidates until April 4 to register. Elections are due to be held on May 25.
Yanukovich’s whereabouts remain unknown after he left the capital Kiev at the weekend. Ukrainian authorities were issuing an arrest warrant for him over his alleged role in the killing of protesters by security forces.
In Washington, the White House indicated it no longer recognised Yanukovich as president.
Jay Carney, the White House spokesman, said although Yanukovich "was a democratically elected leader, his actions have undermined his legitimacy and he is not actively leading the country at present".
Jen Psaki, a US State Department spokeswoman, said in a press briefing on Monday: "Yanukovich left Kiev. He took his furniture, packed his bags, and we don’t have more information on his whereabouts.
"So there are officials who have stepped in and are acting in response to that leadership gap at the moment."
Turchinov has already said his country is ready for talks with Russia to try to improve relations, but has made it clear that Kiev's European integration is a priority.
Turchinov was handed the president's duties temporarily in a vote in the chamber earlier on Sunday.
He portrayed the economy as in dire straits and said economic recovery was a key task.
Turchinov has also warned against growing signs of separatism, particularly in areas near the border with Russia.
Indeed, dozens of pro-Russian protesters rallied on Tuesday in the Crimean Peninsula city of Sevastopol, denouncing politicians in Kiev, with some even calling for secession from Ukraine.
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A Russian legislator stoked their passions by promising that Russia would protect them.
"Russia, save us!" they chanted.
A Russian flag had replaced the Ukrainian flag in front of the city council building in Sevastopol, 800km to the south of Kiev.
An armoured personnel carrier and two lorries full of Russian troops made a rare appearance on the streets, openly demonstrating Russian power in this port city where the Kremlin's Black Sea Fleet is based.
Some called on Russia to protect them from the movement that drove Yanukovich from the capital three days ago.
From Moscow, Sergei Lavrov, Russia's foreign minister, warned on Tuesday that it was "dangerous" to force Ukraine to choose between Russia and the West, a reference to interventions from the US and Europe over the fate of the Eastern European country.
"It is dangerous and counterproductive to try to force upon a Ukraine a choice on the principle: 'You are either with us or against us'," Lavrov said following talks with Jean Asselborn, Luxembourg's foreign minister.