German Chancellor Angela Merkel rejected an accusation from U.S. President Donald Trump’s top trade adviser that Germany is bolstering its exports with a “grossly undervalued” euro in a growing trans-Atlantic spat.

Peter Navarro, the head of the new White House National Trade Council, told the Financial Times that Germany’s advantageous trade position within the EU was one of the main reasons for the demise of a U.S.-EU trade accord, known as the Trans-Atlantic Trade and Investment Partnership. As the administration seeks bilateral trade arrangements at the expense of multilateral deals, Navarro called TTIP “a multilateral deal with many countries under one ‘roof,’” according to written responses to the newspaper’s questions.

Merkel, responding to the report, said the euro exchange rate was the province of the European Central Bank, whose independence has long been upheld by the German government.

“We won’t exercise any influence over the European Central Bank, so I can’t and I don’t want to change the situation as it is now,” Merkel said in Stockholm Tuesday after meeting with Swedish Prime Minister Stefan Lofven. “Beyond that, we strive to trade on the global market with competitive products in fair trade with all others.”

G-20 Summit

The comments by the Trump official aimed at Europe’s biggest economy are an implicit challenge to Merkel, who is presiding over the Group of 20 countries this year on a platform of free trade and plans to host Trump at a summit in July. The euro rose 0.8 percent to $1.0776 at 3:30 p.m. in Berlin.

“A big obstacle to viewing TTIP as a bilateral deal is Germany, which continues to exploit other countries in the EU as well as the U.S. with an ‘implicit Deutsche Mark’ that is grossly undervalued,” the FT quoted Navarro as saying. “The German structural imbalance in trade with the rest of the EU and the U.S. underscores the economic heterogeneity within the EU — ergo, this is a multilateral deal in bilateral dress.”

Navarro’s comments echo Trump’s view, expressed in an interview with European newspapers days before his inauguration, that the EU is “basically a vehicle for Germany.” Trump went on to predict the EU’s possible disintegration as other member states would follow the U.K.’s exit, a process the president has embraced.

German Rebuff

Germany has defended its current account surplus, which climbed to 8.7 percent of economic output last year, against critics who have assailed it as an excessive imbalance that’s strangled economic recovery in the 19-member single currency.

The German Economy Ministry on Monday echoed the chancellor’s remarks that the government has little leverage over global forces affecting the euro’s exchange rate.

“Interest-rate expectations and the resulting impact on the exchange rate is something the German government can’t influence,” ministry spokeswoman Tanja Alemany told reporters in Berlin. “Of course it’s obvious that a low exchange rate against the U.S. dollar makes our products cheaper abroad, which tends to boost exports.”

ECB Friction

German policy makers have instead directed criticism at the ECB for its record-low rates, which are eroding Germans’ interest on savings in an election year. 

“Please don’t criticize the German surplus,” Finance Minister Wolfgang Schaeuble said in an interview with Bloomberg at the World Economic Forum in Davos, Switzerland, on Jan. 19.

In her comments, Merkel said monetary-policy independence was a mainstay of Germany policy stretching back before the euro replaced the deutsche mark in 2002.

“As far as the euro and its valuation goes, Germany is a country that has always called for the European Central Bank to do its work independently, just as the Bundesbank did when there was no euro,” Merkel said in Sweden.