Ukraine president says debt to Russia must be paid

President Viktor Yushchenko accused Prime Minister Yulia Tymoshenko--his political rival despite sharing executive powers--of acting irresponsibly by allowing the debt to accumulate.

He said she bore full responsibility for the problem and that the debt should be settled within the next 5 days.

"I want to warn that such practice leads to a colonization of Ukraine," Yushchenko told a security council meeting.

The two politicians have jostled for power since they formed their coalition last year, so although economic policy is within Tymoshenko's mandate, Yushenko has in the past challenged her decisions by issuing decrees.

The state gas company Naftogaz, which answers to Tymoshenko, continued disputing the size and nature of the debt. Naftogaz said in a statement Friday it actually amounts to $1.3 billion and is owed to an intermediary company, not Russia's gas monopoly Gazprom.

Russian President Dmitry Medvedev ordered Gazprom Thursday to collect the debt from Ukraine, saying Russia would not take no for an answer.

Gazprom head Alexei Miller then threatened to hike the price for natural gas for Ukraine from the current $179.5 per 1,000 cubic meters to over $400.

Tymoshenko, on a visit to Sweden Friday, expressed optimism that Russia would stick by an agreement she reached earlier this year to raise the price gradually over several years.

Russia's disputes with Ukraine over gas prices in the past have led Moscow to cut off or reduce supplies, actions that affected natural gas consumers in Western Europe, too.