Russia is ready to help Ukraine as it seeks to stave off economic collapse, U.S. Secretary of State John Kerry said Friday after talking with his Russian counterpart.

Russian Foreign Minister Sergei Lavrov indicated during a Friday phone call "that they are prepared to be engaged and be involved in helping to deal with the economic transition that needs to take place at this point," Kerry told reporters.

International Monetary Fund chief Christine Lagarde urged calm over Ukraine's economic situation on Friday after the country asked for at least $15 billion in financial aid.

"We do not see anything that is critical, that is worthy of panic at the moment," Lagarde said after talks in Washington on Ukraine with German Foreign Minister Frank-Walter Steinmeier.

Crisis-hit Ukraine's central bank on Friday announced it was imposing a limit of around a 1,000 euros on daily bank withdrawals as the national currency plunges to record lows.

The bank said it was slapping a limit of 15,000 on withdrawals (1,095 euros, 1,400 dollars). The hryvna has plunged nearly 20 percent to record lows since the start of the year as tensions soared between the new pro-West government in Kiev and old master Moscow following the ousting of the country's pro-Russia president.

Swiss authorities said Friday they have launched a criminal probe into alleged money laundering by ousted Ukrainian leader Viktor Yanukovych and his multi-millionaire son.

The government also announced it was freezing the assets of 20 Ukranian officials, including Yanukovych and his son Olexandr and a number of former ministers in his government.

Vietnam has banned its banks from handling Bitcoins, saying the virtual currency is not legal tender in the communist nation.

Bitcoin, invented in the wake of the global financial crisis, is a form of cryptography-based e-money that offers a largely anonymous payment system, but its value is highly volatile.

Japan's recovery is holding steady ahead of a looming sales tax hike, economic indicators showed Friday, though weakness in wages and spending suggest it remains vulnerable to a reversal.

The consumer price index rose 1.3 percent in January and factory production also climbed.

French gas giant GDF Suez reported a huge net loss for last year, the latest gas provider to reveal the depth of upheaval from the boom of shale energy in North America.

The group, which also distributes electricity, reported a net loss of 9.7 billion euros ($13.24 billion) for 2013 from sales which slipped by 0.8 percent to 81.3 billion euros.

Britain's state-rescued Royal Bank of Scotland plunged into a near £9.0-billion loss last year on vast charges for litigation and the creation of a 'bad bank' division, it said Thursday.

The lender, which is 81-percent owned by the government after a huge bailout during the global financial crisis, added it would seek to slash its cost base by another £5.3 billion in the coming years and warned of more "inevitable" job cuts.

Lending to businesses in the debt-mired eurozone contracted again in January, data published by the European Central Bank showed on Thursday.

Private sector loans dropped by 2.0 percent in January in a year-on-year comparison, the ECB said, after already contracting by 2.3 percent in December.

Britain's economy grew by less than thought last year, but still showed the fastest annual growth since before the financial crisis, revised official data showed on Wednesday.

The nation's gross domestic product (GDP) expanded by 1.8 percent in 2013, down from the previous growth figure of 1.9 percent, the Office for National Statistics (ONS) said in a statement giving its latest estimates.