US President Donald Trump said Sunday that the Qatari-donated jet that has served as Air Force One will be sent for upgrades, appearing to acknowledge the plane is not as thoroughly outfitted as older aircrafts.

Stepping off the plane on his return from the FIFA World Cup final in New Jersey on Sunday, Trump was asked about the newly renovated plane’s missile-defense capabilities, amid reports that the new jet is not as secure as the old one.

“It has a lot of capability but, as I understand it, in about a month or so they’re going to send it to have it be maxed out,” Trump told reporters at Joint Base Andrews.

Trump has privately seethed over reporting on the plane’s security deficiencies, and his government has moved aggressively to investigate who talked to reporters about them. Chief of staff Susie Wiles and FBI Director Kash Patel have been personally involved in that effort. A little over a week ago, officials were asked to turn over their phones at the White House.

The New York Times, which first reported on the security issues with the plane, said that four of its reporters were subpoenaed by the government.

Now — despite continuing to fly on the plane — Trump appears to be acknowledging the security concerns are real.

“They’re going to be sending it, and they’ll have it be maxed out. It’ll take about a month,” he said.

Concerns about the new, $400 million Qatari-gifted jet first drew renewed scrutiny earlier this month when Trump unexpectedly ditched the jetduring his return from a NATO summit in Turkey and said he was sending the new plane ahead to Mildenhall air base in England.

Trump said at the time that the change in planes was simply to give US service members stationed at the base “a chance to tour the Aircraft,” downplaying the idea that security concerns were to blame.

But two sources familiar with the matter told CNN the newer plane did not possess the same capabilities to ensure its safety in international settings, though a third said it was equipped with many of the same features as the older plane. Security personnel felt more comfortable with the president aboard the older plane –– which was built from scratch with the commander-in-chief’s safety in mind — rather than the plane that had recently been retrofitted after it was donated by Qatar, officials told CNN.