Billionaire financier George Soros is ready to invest $1 billion in Ukraine if Western countries help private investment there, and sees a 1 in 3 chance Greece will leave the euro, he told Austrian newspaper Der Standard.

Soros has previously urged the West to step up aid to Ukraine, outlining steps toward a $50 billion financing package that he said should be viewed as a bulwark against an increasingly aggressive Russia.

"The West can help Ukraine by increasing attractiveness for investors. A political risk insurance is necessary. This could take the form of mezzanine financing at EU interest rates — very close to zero," he said in an interview published on Monday.

"I stand ready. There are concrete investment ideas, for example in agriculture and infrastructure projects. I would put in $1 billion. This must generate a profit. My foundation would benefit from this. Private engagement needs strong political leadership."

The Hungarian-born hedge fund magnate, who made his name betting against the pound in 1992, also put the chance of Greece leaving the euro zone at a third. Last week he put it at 50:50.

Michael Vachon, spokesman for Soros, said on Monday in a statement: "Soros said he would consider investments in Ukraine if Western leaders demonstrated that they were prepared to 'do whatever it takes' to save Ukraine, including providing adequate budgetary support and political risk insurance.

"Under those conditions, Soros said he would review investments in the energy, agriculture and information technology sectors."