In a bid to bolster President Trump's new executive order suspending travelers from six nations into the U.S., federal law enforcement officials revealed that they are investigating 300 refugees for terrorist ties.

While U.S. officials would not provide details on the FBI investigations, they did say that they are refugees "who either infiltrated with hostile intent or radicalized" since coming into the United States.

To push his point, Trump even included two case studies in his newly revised executive order of refugees convicted of terrorism.

In a background briefing on the president's new immigration suspension from Sudan, Syria, Iran, Libya, Somalia, and Yemen, one official said 300 cases is "truly an alarming number," and added that it is sapping agencies probing the cases.

Apparently some of the refugees have been in the United States for several years, and even become naturalized citizens.

Those 300 are part of a larger group of 1,000 refugees who have been the subject of terrorism investigations by the FBI.

Trump's new order stressed national security as the driver. "This emphasizes the national security threat," said a Justice official.

Another official said that the six nations were picked not because they are Muslim-majority, but because they are either "failed states" or "state sponsors of terrorism."

Critics of the president's earlier executive order, sidelined by a federal appeals court, and the new version overplay the threat of terrorism.

But other reports show the threat, even going back to President Obama's years. ABC News, for example, in 2013 that the U.S. may have let in dozens of terrorists.

Paul Bedard, the Washington Examiner's "Washington Secrets" columnist, can be contacted at pbedard@washingtonexaminer.com