Ukrainian President Viktor Yushchenko warned the European Union Tuesday that Russia might completely cut off Russian natural gas supplies to Europe through Ukraine.

Ukrainian President Viktor Yushchenko warned the European Union Tuesday that Russia might completely cut off Russian natural gas supplies to Europe through Ukraine.

"In the opinion of Viktor Yushchenko, the Russian side intends to either significantly reduce or stop altogether the transit of Russian natural gas" to Europe through Ukraine, the Ukrainian leader said in a message to E.U. leaders.

Yushchenko's office said in a statement he had sent the message to the leadership of the E.U. and the bloc's member states, several of which have reported shortfalls of gas supplied by Russian energy company OAO Gazprom (GAZP.RS).

"I believe it is necessary to inform you that Gazprom has sharply reduced gas supplies to Ukraine for subsequent transit to the European customers as of early Jan. 6, 2009," the statement quoted Yushchenko as saying.

Russia cut gas supply to Ukraine on Jan. 1 over a payment dispute. It then accused Ukraine of stealing Russian gas meant for customers in Europe.

Russian Prime Minister Vladimir Putin Monday ordered an immediate reduction of gas shipped to Europe via Ukraine to compensate for volumes Gazprom said had been illegally siphoned off by Kiev to offset its own shortfall.