Greek Prime Minister Alexis Tsipras vowed Wednesday to go ahead with a controversial bailout referendum despite pressure from European leaders as they declined to consider any fresh debt offer before Sunday's vote.

Hours after Greece became the first advanced economy to default on an IMF repayment, the leftist leader used a live TV address to urge Greeks to vote 'No' on Sunday to creditors' current demands.

Britain on Wednesday urged a swift solution to the Greek crisis, saying it was prepared "for the worst" and ready to defend its economic security after Greece defaulted on its IMF debt.

"It is vital now that the current uncertainty is resolved, whatever the Greek people decide, to ensure economic and financial stability across Europe," finance minister George Osborne said in a statement.

Russian gas company Gazprom said on Wednesday it was halting all natural gas supplies to Ukraine after Kiev announced the immediate suspension of Russian gas purchases the day earlier.

"Ukraine did not pay for July gas supplies," Gazprom said in a statement. "Gazprom halted gas supplies to Ukraine from 10 am (0700 GMT) July 1," it said, stressing that no more gas would be sent to the conflict-torn ex-Soviet country without prepayment.

Inflation rose in Indonesia in June as tens of millions of Muslims observing the Islamic holy month spent extra cash on food, government data showed Wednesday.

The consumer price index rose 7.26 percent year-on-year, the government's Statistics Agency said. Inflation in May was 7.15 percent.

Oil prices eased in Asian trading on Wednesday after Greece missed a 1.5-billion-euro ($1.7-billion) payment to the International Monetary Fund.

In mid-afternoon trade, U.S. benchmark West Texas Intermediate for August delivery was 85 cents lower at $58.62 while Brent crude was down 78 cents at $62.81.

Ukraine announced on Tuesday the immediate suspension of all Russian gas purchases following a breakdown of EU-mediated price negotiations aimed at keeping supplies running for the next three to six months.

The state energy company Naftogaz said it would still continue transporting Russian gas supplies westward to its other European customers.

Greece requested a two-year rescue deal with the EU in a race down to the wire Tuesday, after admitting it would fail to make an IMF payment with just hours left before its EU bailout expires.

The zero-hour appeal came amid a flurry of actions aimed at preventing a chaotic eurozone exit which could have untold repercussions on international markets and the European Union.

Syria, once one of the world's top exporters of pistachios, said on Tuesday that production of the nuts has plunged 50 percent over the past year.

The agriculture ministry said the slump was both the result of the ongoing conflict and frosty conditions last winter.

French mobile company Orange reached a deal with Israel's Partner to retake control of its brand, it said in a statement Tuesday, as it seeks to move on from a major diplomatic spat.

Orange will pay up to 90 million euros ($100 million) to regain direct control of the brand in Israel within two years, which had been licensed to Partner until 2025. 

Hamas on Tuesday closed the offices of Gaza's only mobile telephone company after accusing it of tax-dodging, a move experts said could halt all cellular services in the Palestinian territory.

Police in the Gaza Strip, which Hamas controls, shut the offices of Palestinian telecoms provider Jawwal in Gaza City and left notices proclaiming it was "on the orders of the (Hamas) public prosecutor", an AFP correspondent said.