Iranian 'sleeper cells' inside America have ex-CIA director alarmed

President Donald Trump got a warning from Iran that it has sleeper cells in the U.S. that could act in retaliation for his air strikes over the weekend — and a former CIA director is alarmed.

NBC News' national security and military correspondent Courtney Kube told MSNBC on Monday that in the days leading up to Trump's decision to bomb Iran, the country sent him a private message that those on American soil were not as immune from its retaliation as Trump might believe.

While Iran doesn't possess long-range missiles or bombers that could hit inside the U.S., it warned of "sleeper cells" operating inside the country, two U.S. officials and another person with knowledge told NBC.

"The warning was conveyed to Trump by an intermediary during the G7 summit in Canada," the report continued, citing the three sources.

"Now, of course, this was before President Trump decided to very quickly leave the G7 early on Monday, saying that he needed to come back to DC because he needed to deal with this evolving and tense situation in the Middle East, particularly with the strikes between Israel and Iran," Kube added.

Former CIA Director John Brennan said that he doesn't think Iran will want to "alienate the regional neighbors such as the Gulf states, whether it be Qatar, Saudi Arabia or the UAE."

The U.S. has several bases in the region that could be potential strike sites for Iran, but it would also mean bombing inside one of those neighboring countries.

"Iran has tremendous capability, if they choose, to exercise it, in terms of terrorism, they are the leading state sponsor of terrorism, and they do have assets and sources basically in, you know, Europe, Africa, Middle East, Asia and so on," said Brennan. "And whether or not they have sources here in the United States or assets that could be used to carry out these attacks, I think, is a question. And I know the FBI, DHS, and state and local officials now are looking very closely at any individuals who may be affiliated with the Iranian regime."

When asked about the number of sleeper cells that may be in the country, top Trump advisor Tom Homan confessed he didn't know.

See the clip below or at the link here.