KIEV, April 5 - Ukraine warned on Saturday it would take Russia to an arbitration court if talks with Moscow failed to roll back hikes in the price of natural gas that Kiev called an act of economic aggression.

Russia nearly doubled the price Ukraine pays for its gas this week, forcing Kiev, whose economy is in chaos, to enter into emergency talks with European neighbors to boost cheaper imports from the West.

Ukraine accuses Russia of using the price hikes as a tool of economic pressure after popular protests in Kiev ousted pro-Russian president Viktor Yanukovych in February, souring relations between the two former Soviet republics.