WASHINGTON (REUTERS) - The White House objected to Russia's increase in natural gas prices for Ukraine on Thursday and said markets should determine prices.

White House spokesman Jay Carney spoke after Russian natural gas producer Gazprom announced it would virtually double the gas price for Urkraine to US$485 (S$613) per 1,000 cubic meters this month, which Ukraine said was politically motivated.

"That kind of action taken coercively against Ukraine is something we oppose," Carney told reporters.

"We believe that markets should determine energy prices," he said.