Merkel insists Greek reforms are necessary

German Chancellor Angela Merkel said on Thursday that Greece has no choice but to carry out economic reforms if its wants to receive more financial aid, dashing any hopes Athens might have had for a softening in Berlin's stance.

Tensions over Greece's massive financial bailout overshadowed a European Union summit amid fears that the country could accidently drop out of the eurozone, triggering a crisis across the currency zone shared by 19 nations.

"There can only be a solution on the basis of the agreements reached in the eurogroup," Merkel said, referring to the meeting last month of finance ministers from the countries that use the euro.