KIEV, Nov. 26 - Ukraine’s national oil and gas company, Naftogaz Ukrayiny, says it is unable to buy U.S. dollars on forex market, jeopardizing payments of debts for Russian gas supplies, a top official said Wednesday.

Naftogaz needs to start clearing $2.4 billion debt for earlier gas supplies after Gazprom has recently threatened to cut gas supplies unless Ukraine pays the debt by the end of the year.