"Athens’ proposals are unsatisfactory," Schaeuble said as quoted by the Bild newspaper.
The minister added that he is skeptical about the Greek proposals and would like to stop negotiations with Athens, but noted that German Chancellor Angela Merkel intends to continue the talks.
Eurozone finance ministers are meeting in Brussels on Saturday to discuss whether the proposals on economic reforms made by Athens are sufficient for talks on further financial assistance to recommence.
Ahead of the talks, EU Economic and Financial Affairs Commissioner Pierre Moscovici said that Athens' revised reform plan could become the basis for an agreement between Greece and its lenders.
In a Sunday referendum called by Greek Prime Minister Alexis Tsipras, over 61 percent of Greek voters rejected the unpopular austerity measures demanded by Athens' major international creditors in exchange for further financial assistance.
Greek Prime Minister Alexis Tsipras said Saturday that his new post-referendum reform program falls short of the promises he made to the Greek people, but is an improvement over the rejected lender-proposed package.
Without additional financial assistance, Greece will not be able to pay back the immense debt accumulated by previous governments.