Underlying the East-West tug-of-war,Sweden's foreign minister, Carl Bildt, accused Moscow on Monday of trying to woo Kiev with propaganda and "sometimes outright lies".
His Russian counterpart Sergei Lavrov, meeting EU foreign ministers in Brussels, took a veiled swipe at the bloc by criticising "external intervention" in Ukraine.
(Read more: Ukraine opposition decries Russia talks, reports of deal denied)
Ukraine is seeking help to cover an external funding gap of $17 billion next year - almost the level of the central bank's depleted currency reserves.
Putin aide Belousov did not say how much Russia, whose own economy is stuttering badly, would be ready to offer Ukraine. But sources in Ukraine said the deal could be worth $15 billion, with Russian providing about $3-5 billion up front.
The most Brussels has so far offered Ukraine is 610 million euros ($838 million) but EU officials are in discussion with the International Monetary Fund, the World Bank and other financial institutions on ways to help Ukraine.
(Read more: Ukraine protests increase currency risk)
Apart from loans, Ukraine is seeking a lower price for Russian gas - now at around $400 per 1,000 cubic metres - to help it cope with its debt burden.
Ukrainian Prime Minister Mykola Azarov says he hopes a deal on cheaper gas prices will soon be concluded. A reduction of at least 10-15 percent is likely, sources in Kiev said.
Tuesday's talks are intended to conclude a "substantial package" of agreements to chart out a road map to removing trade barriers for Ukraine with Russia, both sides say.
(Read more: Russia plays down 'gas war', warns Ukraine on EU)
Yanukovich is seeking the best deal possible for Ukraine but playing East against West is a hazardous manoeuvre running the risk of alienating both parties and there is no certainty Ukraine can avoid defaultor a currency crisis.
Putin regards Ukraine as vital to creating a political and economic union stretching from the Pacific to the EU's borders. But Yanukovich is not expected to sign Ukraine up for a Russia-led customs union which Putin sees as the basis for this.
Holding out on membership of the customs union could be Yanukovich's last bargaining chip as he tries to survive the protests in Kiev and win a presidential election in 2015.
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