Border czar Tom Homan revealed Sunday that 1,272 Iranian nationals were released during the Biden administration, who were among the “over 10 million people” who crossed into the United States illegally.

Homan’s warning comes after President Donald Trump announced on Saturday night that the U.S. struck Iran, in which “a full payload” of bombs was dropped on three nuclear sites in the country. The border czar was asked about the possibility of sleeper cells occupied by Iranians in the U.S., to which he reiterated his national security concerns posed by the last administration’s handling of the border and how it greatly contrasts with Trump’s security of it.