Germany’s Federal Aviation Office has revoked the license of Iranian airline Mahan Air over security concerns and the company’s continued involvement in allegedly transporting members of the Iranian Revolutionary Guard Corps and the Lebanese Shiite terrorist group Hezbollah both to and from the civil war in Syria.

The German regulatory office involved in the final decision said the government opted to ban Mahan after having consulted with Berlin’s other European allies and the United States.

“It cannot be ruled out that this airline carries out transports to Germany that affect our security concerns,” German government spokesman Steffen Seibert said on January 21 during a news conference in Berlin, adding, “This is especially true against the backdrop of terrorist activities, intelligence on terrorist activities from the Iranian side and Iranian entities in Europe in the past.”

Iran’s second-largest airline, Mahan Air has been under US sanctions since 2011. Washington has in the past threatened to impose sanctions on either countries or firms that offer Mahan landing rights or ground services.

While reiterating the German government’s support for the 2015 Iran nuclear deal that US President Donald J. Trump walked out of last year, Germany’s Foreign Minister Heiko Maas said Berlin would act accordingly to incidents that were a direct threat to German national security. His statement comes only days after an Afghan citizen was arrested on allegations that he spied for Iran’s intelligence services, which are also a part of the Revolutionary Guard Corps, while working as a translator for the Bundeswehr, the German army.

US Secretary of State Mike Pompeo took to Twitter to voice his support for the German government’s decision. Pompeo has, along with National Security Advisor John Bolton, been instrumental in trying to urge the US’ European allies to take a tougher line with Tehran.

The European Union has stepped up its efforts combat Iran’s clandestine activities in recent weeks after reports emerged that the Revolutionary Guard Corps, or IRGC, had actively attempted to carry out multiple assassination attempts on European soil, targeting individuals who actively oppose the Islamic Republic’s regime.

Prior to the announced ban, Mahan had been running four flights to Germany each week, as well as to France, Italy, Spain, and Greece.