The exchange rate of the US Dollar and the Euro, at top, is displayed in the window of a currency exchange office in Berlin, Monday, Jan. 5, 2015. The euro sank to a nine-year low Monday as new doubts surfaced about Greece's commitment to the common currency bloc. European stocks mostly rose while Asian markets were mixed. (AP Photo/Markus Schreiber) (The Associated Press)
BRUSSELS – The European Union's executive Commission says membership in the euro bloc is "irrevocable" but leaves it open to what extent Greece could renegotiate the terms after the Jan. 25 elections.