Vyacheslav Kovalchuk, head of the foreign ministry's second CIS department, told a news conference that once Russia had joined the WTO, it would raise domestic gas prices.
"If Russia joins the WTO, the gas price will also be raised for Belarus," the diplomat said.
The global trade body has pressured Russia to increase domestic prices for gas and other fuels, whereas Russia has insisted on its right to what it calls natural advantage.
Kovalchuk added, however, that it would be logical for Russia and Belarus, who have been working since 1999 on establishing a union state, to have common prices for natural gas.
The two former Soviet nations signed an agreement in December 1999 to restore a common political, economic, legal, defense, and humanitarian space while retaining their sovereignty. The plan, however, has largely gathered dust, although occasional steps forward have been made.
Russian natural gas monopoly Gazprom said in late March that it would raise gas prices for Belarus, which transits Russian gas into Europe, to European levels starting in 2007.
Under a contract between Gazprom and Belarus' Beltransgaz signed in December, Gazprom will deliver 21 billion cubic meters of gas this year at $46.68 per 1,000 cubic meters, the same as last year.
Gazprom said the price of gas and transit took into account the future Russia-Belarus Union State, which implies single standards for financial and economic indicators.
The Russian energy giant first raised the gas price for Belarus in 2005. Late last year, Russia gave its neighbor a $146-million loan to cover gas price hikes.
