The US has demonstrated "very little willingness to take the arguments of its allies seriously," German Foreign Minister Heiko Maas told the German magazine Spiegel.
Donald Trump's decision to leave the Iran nuclear agreement has caused serious damage to relations between the United States and Germany in the long-run, the top diplomat stated.
"The transformation which the US is undergoing has already taken hold of transatlantic ties," Maas said, adding that Berlin was aware of the ongoing change "before Tuesday night's disappointment."
According to Maas, Germany will pursue a tougher policy toward the United States when it comes to defending Berlin's interests.
"We are prepared to talk, negotiate and also fight for our interests where necessary," the diplomat told the magazine. "This goes for all levels, not just for the White House."
US President Donald Trump earlier this week announced that the United States would withdraw from the Iran nuclear deal, formally known as the Joint Comprehensive Plan of Action (JCPOA). He also vowed to re-impose the highest level of economic sanctions against Iran in response to Tehran's alleged development of its nuclear program.
READ MORE: Iran Deal: Trump's Pullout May Result in Three Scenarios, Benefits for Russia
Following Trump's announcement, the Russian and China's foreign ministries stated that they will remain committed to the Iranian nuclear deal and expressed regret over the US decision to pull out of the deal.
On July 14, 2015, the deal was signed by the European Union and the P5+1 group of countries — China, France, Russia, the United Kingdom and the United States plus Germany. The accord stipulates the gradual lifting of anti-Iranian sanctions in exchange for Tehran curbing its nuclear program and allowing inspections to ensure that the nature of the program is peaceful.