BERLIN (Reuters) - The U.S. ambassador to Germany urged Berlin on Tuesday to stop Iran withdrawing large sums of cash from bank accounts in Germany to offset the effect of new U.S. sanctions imposed after Washington withdrew from a 2015 nuclear deal.

FILE PHOTO: German Chancellor Angela Merkel receives the ambassador of U.S. to Germany, Richard Grenell, in Meseberg, Germany July 6, 2018. REUTERS/Axel Schmidt/File Photo

Richard Grenell, a longtime critic of the accord, told the mass-circulation daily Bild that the U.S. government was extremely concerned about Tehran’s plans to transfer hundreds of millions of euros in cash to Iran.

“We encourage the highest levels of the German government to intervene and stop the plan,” Grenell said.

Iran curbed its nuclear activity under the deal and won relief from international sanctions. The other signatories including U.S. allies Germany, France and Britain have reaffirmed the deal, seeing it as crucial to preventing a Iranian nuclear weapon. Trump denounced it as badly flawed in Iran’s favor.

Grenell’s comment drew a rebuke from Johann Wadephul, deputy leader of Chancellor Angela Merkel’s conservatives in parliament, who said the transaction should not be blocked on political grounds if it passed legal muster.

“The statement of the U.S. ambassador is once again unsettling and difficult to reconcile with his diplomatic role,” Wadephul told Reuters.

A German finance ministry spokeswoman said German authorities were examining the Iranian request according to clearly prescribed guidelines aimed at averting risks linked to money laundering or possible financing of extremist groups.

“Naturally it’s clear that part of the German government review will also look at whether there could be a violation of a sanctions regime,” a foreign ministry spokesman said.

Bild first reported on Monday that German authorities were considering a request by Iran to withdraw 300 million euros ($350 million) from bank accounts held in Germany and to transfer the cash to Tehran.

Critics say Grenell has repeatedly overstepped the bounds of his role as President Donald Trump’s envoy to Berlin, including with his recent meetings with German car company executives about a deal on European duties on U.S. cars.

Grenell has sparked controversy by adopting a far more outspoken role than his predecessor since arriving in Berlin in May, including a posting on Twitter in which he said German firms should wind down their business in Iran after Trump’s decision to pull the United States out of the nuclear accord.