BERLIN (Reuters) - European Union member states must give the EU trade commissioner a clear mandate for negotiations with the United States over a long-term exemption from U.S. metal tariffs, German Chancellor Angela Merkel said on Wednesday.

FILE PHOTO - German Economic Minister Peter Altmaier leaves after delivering a statement regarding the Trump Administration's steel and aluminium tariffs, outside of the White House in Washington, U.S., March 19, 2018. REUTERS/Leah Millis

A top German minister earlier acknowledged differences on trade with France, only days after U.S. President Donald Trump extended a temporary reprieve for the EU on steel and aluminum tariffs.

“Of course, we think it’s important that there are exemptions not only for a limited period of time,” Merkel said during a joint news conference with Slovak Prime Minister Peter Pellegrini in Berlin.

Asked whether there was a rift between Germany and France on how to respond to the U.S. trade threat, Merkel said: “So far, we have had a very united stance, namely that we view these tariff demands as unjustified and that we want a long-term exemption.”

Earlier on Wednesday, German Economy Minister Peter Altmaier was asked whether it would be easier to find a common stance with France or formulate an offer to the United States. “Both are equally difficult,” he told Germany’s ARD television.

Merkel said talks between European trade and economy ministers would continue to give Trade Commissioner Cecilia Malmstrom a clear mandate for her negotiations with the U.S. administration.

The White House announced on Monday that Trump had extended a exemption from the tariffs for the EU, Canada and Mexico until June 1, just hours before they were due to come into force.

The European Commission, the EU’s executive arm, has called for a permanent exemption, arguing the one-month extension is causing uncertainty among businesses. But there are differences in emphasis among member states.

The priority for export-oriented Germany, Europe’s biggest economy, is to get a broad agreement to lower tariffs across a broad spectrum of products, especially in manufacturing.

The United States is Germany’s most important export destination after the bloc of EU countries, and its exports account for roughly 47 percent of German economic output.

By contrast, France has said it agrees that over-capacity exists in steel and aluminum and it is ready to work with the United States to resolve those issues. But no such discussions can occur unless the EU is permanently excluded from unilateral tariff increases, the French say.