Russia has agreed to pay Turkmenistan up to 50% more for its gas, Russia's gas export monopoly, Gazprom, has said.
Gas is one of the fault lines of Ukraine's relationship with Russia
Analysts say the increase will push up prices for Ukraine, which has had past disputes with Russia over gas supplies.
Gazprom buys almost all the gas exported by Turkmenistan and sells it on to other countries.
The higher price will help gas-rich Turkmenistan to speed up construction of a new Caspian Sea pipeline through Kazakhstan to Russia.
The state-run Gazprom, which supplies 25% of Europe's gas, currently buys Turkmen gas for $100 (£48) per 1,000 cubic metres.
The price will rise in 2008 to $130, then rise again in the second half of the year to $150, Gazprom said.
The giant gas company controls Turkmenistan's gas exports since the country relies on Gazprom's Soviet-era pipeline system.
Ukraine is currently negotiating prices with Gazprom and analysts say next year's prices could rise to $190.
Ukraine's energy ministry said it was not yet clear how much a price increase Ukraine would be faced with.
The country's Economy Minister, Anatoly Kinakh, said a price of $180 or more per 1,000 cubic metres would have an extremely negative impact on Ukraine.