US President Donald Trump, who lost last week’s election to Democratic challenger Biden, pulled the US out of the multilateral agreement signed between Iran and world powers – France, Britain, Germany, Russia, China and the US – in 2018 and launched a campaign of “maximum pressure” against the Islamic Republic by imposing tough sanctions that targeted Iran's vital oil industry and banking ties, among other sectors.
Maas told German public-broadcasting radio station, Deutschlandfunk, that “it is very difficult to get anything done” when the United States has a strategy of maximum pressure and Europe has “a strategy of negotiation”.
“This is not going to work. We have to get back together,” the top diplomat said.
Maas expressed optimism that “there will be a debate in the US about whether [the country] should rejoin the agreement”.
He said Europe and the US need to talk immediately about unifying their strategies regarding the nuclear accord.
“We will achieve nothing with Iran… if Europe and the US pursue two completely different strategies. This has to come to an end,” Maas said.
Iranian President Hassan Rouhani urged the next US administration on Sunday "to compensate for its previous mistakes" following Biden's victory in the presidential election.
Rouhani said the Iranian people's "heroic resistance against the imposed economic war" by the Trump administration "proved that America's maximum pressure policy is doomed to fail."
"Iran favors constructive interaction with the world,” he added.
Biden has said during his campaign that he plans to embark on a "credible path to return to diplomacy" with Iran, and pledged to rejoin the accord if Iran also returns to full compliance.
In retaliation for Trump's actions, Iran has gradually reduced its commitments to the deal. But the Islamic Republic has made it clear that those steps were reversible if its interests were respected.
Biden has said returning to the agreement would be "a starting point for follow-on negotiations" and that Washington would then work with allies to strengthen and extend the nuclear deal and address other issues of concern.
Iran has ruled out any talks aimed at further curbing the country’s nuclear activity, halting its ballistic missile program and limiting the Islamic Republic’s regional influence.
AFP and Reuters contributed to this story.