European leaders said Greece is running out of time to unfreeze the aid needed to keep the country afloat as they scramble to draw up contingency plans should negotiations collapse.

Germany is working on a proposal that would allow Greece to stay in the euro in the event of a sovereign default, weekly newspaper Die Zeit reported today, without citing anyone.

"What the government is working on is that the euro region is kept together and strengthened," Friederike von Tiesenhausen, a German Finance Ministry spokeswoman, said today in Berlin when asked about the report. "There are lots of discussions on this currently and negotiations."

European officials are expressing skepticism that there’s enough time to work out a deal ahead of a meeting of euro-area finance ministers on April 24 in Riga, Latvia, to assess whether Greece has made enough progress to warrant a disbursement from its 240 billion-euro ($254 billion) bailout fund. Leaders are pressuring Greece to submit specific reforms by early next week as the country runs out of cash and faces debt payments and monthly salary and pension obligations in the coming weeks.

"Negotiations with Greece are ongoing," Tiesenhausen said. "This is a complex process and no one in the euro group expects that this could completed by April 24."

Greece fell short of its budget targets last year, prompting new concerns about the cash-strapped nation’s ability to pay bills as government officials met with creditors in Athens Wednesday. The most-indebted state in the euro area posted a budget surplus before interest payments of 0.4 percent of gross-domestic product last year, its statistics office said. That compared with a target of 1.5 percent set out as terms of a bailout package.

The figures come a day after the European Central Bank was said to have raised the ceiling on Emergency Liquidity Assistance to Greece, leaving the nation’s lenders with a buffer of about 4 billion euros.

"Greece is moving increasingly close to the abyss," Slovak Finance Minister Peter Kazimir told reporters in Bratislava. "Nothing can be excluded."