The European Union must decide on a way to help debt-laden Greece this week or run the risk of causing a "serious disruption" for the euro, the European Union's monetary affairs chief said.

"There is already the technical preparedness. Now we need a political decision. This is also important to Greece so it would know what to expect," Economic and Monetary Affairs Commissioner Olli Rehn was quoted as saying in the Finnish daily Helsingin Sanomat.

"We are at a crossroads. Greece can cause a serious disruption (to the euro ), or we can can learn from this crisis."

Rehn said there were still a number of alternatives on the table to help Greece, and he saw no problems with the International Monetary Fund (IMF) assisting Greece. "The EU is close to the IMF. We are partners."

France and Spain have called for a special meeting of euro zone countries this week to discuss Greece ahead of the regular two-day EU summit which opens on Thursday afternoon.

Greece needs to refinance some 16 billion euros ($21.6 billion) in maturing debt between April 20 and May 23 and is hoping that a public display of an EU emergency support mechanism, which would not need to be activated, will be enough to force down the cost.

The crisis over Greece's debt, expected to hit 120 percent of national output this year, and its budget deficit, which reached 12.9 percent of GDP last year, has shaken confidence in the euro single currency.