Samaras told reporters in Berlin on Tuesday that his country is "delivering and Europe is helping."
Greece has been struggling under the weight of massive government debts that required a series of international bailouts.
Germany and others have demanded sharp cuts in public spending in return for the financial aid.
Samaras said he saw "the glass half full" and had come to Berlin with a message of optimism.
He spoke ahead of a closed-doors conference organized by German newspaper Die Welt.
Samaras was due to meet Merkel later in the day.