EU Energy Commissioner Guenther Oettinger on Friday said he hoped high-stakes gas talks between Ukraine and Russia to avert a cutoff of energy flows to Europe could resume this weekend.
"We agreed that both delegations talk to their respective presidents and prime ministers and that happened yesterday," Oettinger said as he arrived for a meeting with EU energy ministers.
"On this basis I am expecting that we continue tomorrow, on Saturday, the talks between the minister of Ukraine and the minister of Russia and the CEOs of the gas companies and their delegations," the commissioner said.
"I am expecting a phone call in the next three to four hours," he said, adding that he was willing to meet anywhere.
The latest round of EU-brokered talks broke up on Wednesday in Brussels with Ukraine calling Putin's offer to lower Kiev's fuel price by more than 20 percent a "trap".
But Gazprom head Alexei Miller said on Thursday that Russia had already twice postponed its payments deadline and would unquestionably halt supplies should Ukraine fail to come through on a nearly two billion dollar debt payment (1.45 billion euros) "by Monday at 10 o'clock in the morning."
Ukraine's President Petro Poroshenko on Thursday held his first telephone talks with Russia's Vladimir Putin since he was sworn in at the weekend.
Putin and Poroshenko shook hands on the sidelines of D-Day commemorations in France on June 6, but relations between their two countries remain extremely tense.