(Bloomberg) -- The new leader of Chancellor Angela Merkel’s party took the U.S. ambassador to Germany to task for warning companies involved in a Russian gas pipeline that they could face sanctions.

Annegret Kramp-Karrenbauer -- who last month succeeded Merkel as leader of the Christian Democratic Union -- dismissed letters sent by Richard Grenell to companies involved in the Nord Stream 2 pipeline as an “unusual” diplomatic move that wouldn’t impact the project to boost Russian gas supplies to Germany. Grenell is a close ally of President Donald Trump.

“The American ambassador operates in a, shall I say, somewhat unusual diplomatic manner,” Kramp-Karrenbauer told reporters in Potsdam outside Berlin on Monday. “He’s shown that not only through this letter but also from when he took office.”

Kramp-Karrenbauer was more outspoken than Merkel’s government, which avoided criticism of Grenell’s move at a briefing with reporters on Monday. The former premier of the state of Saarland is trying to emerge from the chancellor’s shadow as Germany’s ruling party prepares for potential national elections if the coalition with the Social Democrats falls apart.

Grenell, who provoked furor in Berlin the day he took office last May by calling on German companies to exit Iran, told the companies that their involvement in the direct gas link between Russia and Germany risked coming under U.S. sanctions.

‘Right Response’

The U.S. has criticized the $11 billion pipeline project as a security threat that will make the European Union too reliant on Russian energy. Merkel’s government supports it with political caveats such as ensuring continued gas transits through Ukraine, even though backing within her coalition has softened in recent months.

The 1,200-kilometer (750-mile) undersea pipeline is being constructed by Russia’s Gazprom PJSC. U.S. restrictions would potentially hit companies in Austria, France, Germany and the Netherlands. Royal Dutch Shell Plc, BASF SE’s Wintershall unit, Uniper SE, OMV AG and Engie SA are Gazprom’s partners in the project.

Germany’s Bild am Sonntag newspaper first reported Grenell’s letter. The U.S. embassy countered, saying the letter was coordinated within the Trump administration and reflects the longstanding U.S. position as well as that of EU member states who oppose Nord Stream. It also took issue with Bild’s characterization of the letter as blackmail, saying the message wasn’t meant as a threat.

“The only thing that could be considered blackmail in this situation would be the Kremlin having leverage over future gas supplies,” an embassy spokesman said.

Germany’s Foreign Ministry on Monday declined to address Grenell’s move directly. Spokeswoman Maria Adebahr told reporters that the ministry addresses issues “openly, professionally and directly” with U.S. counterparts.

Kramp-Karrenbauer said German industry has already offered “the right response” to the Grenell letter, “which is that they won’t allow themselves to be threatened and that they won’t allow this type of intervention.”

To contact the reporter on this story: Patrick Donahue in Potsdam, Germany at pdonahue1@bloomberg.net

To contact the editors responsible for this story: Ben Sills at bsills@bloomberg.net, Chris Reiter, Iain Rogers

©2019 Bloomberg L.P.