BRUSSELS -- European Commission President Jose Manuel Barroso has appealed to Moscow not to halt gas deliveries to Ukraine.
In a letter to Russian President Vladimir Putin, Barroso said "the contractual reliability of the Russian Federation as a supplier of gas is at stake."
Barroso was responding to an earlier letter from Putin in which he warned Russia could partially or completely turn off gas deliveries to Ukraine in the event of "further violations of the conditions of payment by Ukraine."
Moscow this month raised the price it charges Kyiv for gas by 80 percent and said it awaits $2.2 billion in unpaid bills.
In his letter to Putin, Barroso also noted that "changes to contractual arrangements due to political circumstances run counter to the spirit of support and cooperation enshrined in your letter."
In his annual question-and-answer session on April 17, Putin said Russia will wait one month for Ukraine to start paying off its gas debt before asking for prepayment for gas supplies.
He also said he believes it is "impossible" for Europe to stop buying Russian gas and that he was hopeful a deal could be reached with Ukraine on gas supplies.