The Trump administration has threatened to hit European automobile imports with a 25 per cent tariff if Britain, France, and Germany do not formally accuse Iran of breaking its 2015 nuclear deal, The Washington Post reports.

The U.S. has been threatening to hit European vehicles with tariffs for many months over a variety of reasons but those threats have been used by Trump to receive better terms within the U.S.-European trade relationship. The Washington Post reports that this latest threat has been intended to shift European foreign policy.

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However, such tariffs are unlikely to be implemented as the three European nations at the center of the issue have already started to press Iran.

On Tuesday, Britain, France, and Germany triggered a dispute mechanism under the nuclear deal to enforce the agreement requiring Iran to curb its nuclear program. Al Jazeera reports that the dispute mechanism amounts to a formal accusation against Tehran that it broke the terms of the deal. It is understood that the nations had signaled an intention to trigger the dispute mechanism for weeks, long before the Trump administration made the tariff threat.

The U.S. itself withdrew from the nuclear deal back in 2018. Washington said it did so as part of a strategy to force Iran back to the negotiating table to iron out a new deal.

Iran has denied that its nuclear program is aimed at building a bomb but has gradually rolled back its commitments under the agreement since the U.S. withdrawal.