U.S. President Donald Trump has thanked Albania for expelling the Iranian ambassador and another diplomat for allegedly engaging in illegal activities that threaten Albania’s security, AP reported.

Trump’s letter to Albanian Prime Minister Edi Rama, dated Dec. 14, thanked him “for your steadfast efforts to stand up to Iran and to counter its destabilizing activities and efforts to silence dissidents around the globe.”

The U.S. Embassy in Tirana published the letter on its Facebook page on Thursday.

Albania’s Foreign Ministry on Wednesday said the two diplomats were expelled for “violating their diplomatic status” following talks with other countries, including Israel.

Trump’s letter said the expulsion “exemplifies our joint efforts to show the Iranian government that its terrorist activities in Europe and around the world will have severe consequences.”

Iran blamed the United States and Israel for the expulsions. The official IRNA news agency quoted Foreign Ministry spokesman Bahram Ghasemi as saying that “Albania has become an unintentional victim of the United States, Israel and some terrorist groups.”