Maas told German newspaper Bild am Sonntag that "pure threats" and "military actions and threats" against Iran did not work, DW reported.
Tensions between Washington and Tehran have been running high since Trump withdrew from the Iran nuclear deal in May 2018,
The US assassination of top Iranian General Qassem Soleimani in early January followed by Iranian retaliatory attacks on US forces in Iraq further escalated tensions.
The German foreign minister emphasized that dialogue was necessary to make progress on Iran and to promote Europe's Iran strategy.
"If one wanted to improve the situation of the Iranians, it would be useless to stop the dialogue," Maas said. "We have to talk with Iran… We want to prevent a conflagration in and around the Middle East."
"The EU is counting on diplomacy instead of escalation," he said.
Maas said that while the US withdrew from the nuclear deal and is pushing for maximum pressure against Iran, France, Great Britain and Germany wanted instead "to make progress through negotiations" and keep the nuclear treaty in place.
The top diplomat also called on Tehran to return to complying with the 2015 nuclear agreement.
Under the deal, Iran curbed some aspects of its nuclear program in return for the lifting of economic sanctions. Germany, France and the UK are still trying to salvage the agreement.
In response to US sanctions, Iran began to roll back its commitments to the deal in May 2019 in a phased fashion.