Kiev has requested a restructuring of its debt to Russia but Moscow is expecting its $3 billion loan to be repaid in full this year, Russia's finance minister said Tuesday.

"Ukraine asked us to review the issue of restructuring its debt," Finance Minister Anton Siluanov told Russian media on the sidelines of the G20 summit of finance ministers and central bank chiefs in Istanbul.

Standard and Poor's has lowered the outlook for the world's top oil exporter Saudi Arabia to negative and downgraded its Gulf partners Oman and Bahrain on sliding oil prices. 

But despite the large budget deficit planned by Riyadh for this year, the agency maintained its sovereign credit ratings for the kingdom, as well as neighboring Abu Dhabi and Qatar, citing their "very strong fiscal positions."

Oil prices fell in Asia on Tuesday after the International Energy Agency (IEA) predicted that global oil prices will recover only partially over the next five years, analysts said.

U.S. benchmark West Texas Intermediate (WTI) for March delivery slipped 74 cents to $52.12, while Brent crude for March eased 77 cents to $57.57 in afternoon trade. 

Greece's radical new government on Tuesday was fine-turning details of a controversial reform deal it hopes to seal with skeptical EU creditors at critical talks this week in order to liberate the country from a "toxic" bailout.

At talks kicking off with an emergency meeting of eurozone finance ministers Wednesday, Greece will plead its case for stop-gap financing, with a view to clinching an austerity-free reform deal to run from September 1.

A Russian business lobby group made a push Tuesday for Japanese investment as its economy struggles under Western sanctions linked to its role in the Ukraine crisis.

Even as the United States and Europe delayed another round of measures while they push a peace plan, Moscow is looking for cash to replace money that has fled, hoping to tempt resource-poor Japan with oil and gas.

The former HSBC employee who leaked sensational secret documents alleging the bank helped wealthy customers dodge millions of dollars in taxes warned Tuesday that the revelations are just the "tip of the iceberg".

The files created global shockwaves on Monday, spotlighting the financial dealings of the world's ultra-rich and prompting British lawmakers to launch an inquiry into the London-based bank.

Pakistani and Indian officials Monday failed to reach agreement on the resumption of trade across their de facto border in the disputed territory of Kashmir, Pakistani officials said.

Trade was suspended after Indian authorities Friday detained a Pakistani truck driver accused of drug trafficking.

A Belgian judge is considering issuing international arrest warrants for the directors of the Swiss division of HSBC, an official said Monday, as the bank faced a row over revelations that it helped wealthy clients dodge tax.

The threat came as HSBC faced controversy over a cache of "SwissLeaks" documents published at the weekend that claim the bank handled secret accounts for drug lords, tax evaders and celebrities.

Investors in a Hong Kong-based Bitcoin trading company fear they have fallen victim to a scam after it closed down, a lawmaker said Monday, adding losses could total HK$3 billion ($387 million).

Leung Yiu-chung said his office recently received reports from dozens of investors in Hong Kong who paid a total of HK$40 million ($5.16 million) into the scheme run online by MyCoin, but the total loss may be vastly more.

A Greek exit from the euro would see the euro collapse like a house of cards, Finance Minister Yanis Varoufakis warned in comments that triggered a spat with Italy.

"Greece's exit from the euro is not something that is part of our plans, simply because we believe it is like building a house of cards. If you take out the Greek card, the others will collapse," Varoufakis said in an interview with Italian public broadcaster RAI that was aired on Sunday.