President Donald Trump abruptly switched aircraft before departing Ankara, Turkey, earlier this month after U.S. officials determined there was a credible threat from Iranian proxy forces targeting him and whatever aircraft he was traveling on, according to a New York Times report that cited anonymous officials. He had arrived in Ankara on the new Qatari-donated Boeing 747-8 for the NATO summit.

After U.S. officials detected the threat, the Secret Service recommended that Trump change aircraft before leaving the country, the sources told the Times. According to the report, U.S. officials did not believe the Iranian proxy forces were specifically targeting the new Boeing 747-8. Instead, the intelligence indicated the threat was directed at Trump himself and whichever aircraft he was on at the time.

The newly reported details help explain why the White House quickly decided to swap aircraft. They also highlight ongoing security concerns surrounding the Qatari-donated jet, which Trump had pushed to have ready for use as soon as possible, despite its lack of the same advanced defensive systems as the older Air Force One.

Trump has previously spoken publicly about threats from Iran against his life. He has said he left standing orders for the U.S. military to destroy Iran “at levels they’ve never seen before” if Tehran carries out its longstanding threats to kill him.

The revelations come as Trump reportedly mulls escalating attacks on Iran in the ongoing conflict after a ceasefire deal recently broke down. Trump has vowed “major military punishment” for Tehran and its Houthi allies in Yemen, though he once again left open the door to a diplomatic deal with Iran.

“We are talking to them. I think they’re being serious. I think they are being by far the most serious that we’ve seen them, but that doesn’t mean we get there,” Trump told reporters at the White House on the day of the report. He added: “We’re locked and loaded. We’re ready to go.”

The Trump administration’s Justice Department had previously subpoenaed reporters at the New York Times over their coverage of security risks involving the Qatari-gifted Air Force One replacement, but the department has dropped those efforts for now, according to the Times.