"Unilateral deals at the expense of the allies will harm the United States, too. The one who hits his partners risks to lose eventually," Maas told the German Bild am Sonntag newspaper in an interview, released on Sunday.
The German foreign minister also expressed hope that the US-Russian high-level talks would help reach progress in nuclear disarmament.
Trump and Putin will meet in the Finnish capital on Monday. Officials from both nations have said that Syrian and Ukrainian crises, as well as bilateral relations will be on the talks agenda.
Earlier this week, Trump met with German Chancellor Angela Merkel on the sidelines of the NATO annual summit in Brussels. The meeting was held amid Trump's criticism of Germany over what the US president called the excessive reliance of Berlin on Russian gas. Merkel denied Trump's claims that Germany was a "captive" of Russia, saying that Berlin acted independently in its foreign policies.