Germany's finance minister is keeping the pressure on Greece to implement reforms and spending cuts before a visit by Chancellor Angela Merkel.

Merkel travels to Athens on Tuesday. Finance Minister Wolfgang Schaeuble rejected on ZDF television Sunday suggestions that the trip signals Greece will definitely get further bailout money from its creditors.

Greece's debt inspectors are currently assessing whether Athens has made enough progress to secure the next €31 billion ($40 billion) tranche of its bailout. Schaeuble stressed that "Greece must fulfill its obligations, so that the next tranche can be paid out."

He also underlined the need for Greece to regain competitiveness and said: "Those in Greece who tell people that Europe or even the German chancellor are to blame for their problems are lying to people in Greece."