Russian and Ukrainian negotiators will meet again Friday on a natural gas price dispute that Russian President Vladimir Putin calls a "real crisis."

Russia's state-run Gazprom plans to quadruple the price it charges Ukraine for natural gas. It says it will cut off exports to Ukraine Sunday if no agreement is reached.

Mr. Putin Thursday berated senior negotiators from both countries Thursday, accusing them of creating a political and energy crisis between Russia and Ukraine.

He offered Ukraine a $3.6 billion loan to help pay for the higher price.

Ukrainian President Viktor Yushchenko rejected the offer. He said Ukraine will use its own means to pay for gas at what he calls an objective and reasonable price.

Gazprom says the higher gas prices are in line with world markets. Ukraine calls them economically damaging.

Some information for this report provided by AFP and AP.