BRUSSELS — Greece formally asked for a three-year bailout from the eurozone’s rescue fund, according to a copy of the letter seen by The Wall Street Journal, though Germany said it wouldn’t consider the request until it sees a full list of reforms.

Pressure is growing on both sides to come to some kind of deal and avert a potentially imminent Greek exit from the euro. U.S. Treasury Secretary Jacob Lew said for the first time publicly Wednesday that Europe needs to restructure Greece’s huge debt as a key part of an emergency-financing solution, a move Germany has resisted.