President Donald Trump on Friday announced he’s considering a “big order” of advanced Super Hornet fighter jets designated F/A-18XT and made by Boeing Co.

“We are looking seriously at a big order,” he told the audience at Boeing’s South Carolina facility during the unveiling of the company’s 787 Dreamliner. “Do you care if we use the F-18 Super Hornets?”

The comments came less than a month after Defense Secretary Jim Mattis ordered a review of the F/A-18E/F Super Hornet, a fourth-generation fighter, as a potential lower-cost alternative to the F-35C Joint Strike Fighter, the carrier version of a fifth-generation fighter made by Lockheed Martin Corp.

The remarks also came a day after Robert Harward, a retired vice admiral and former Navy SEAL who went on to become an executive at Lockheed, declined an offer to succeed Michael Flynn as national security adviser.

According to White House pool reports from the Trump event, Reince Priebus, Trump’s chief of staff, was spotted holding a brochure for the “F/A-18 XT.” The XT is the Advanced Super Hornet, or the Block III fighter jet concept for the Navy, a Boeing spokesman confirmed to Military.com.

“While Boeing demonstrated advanced Super Hornet capabilities in flight in 2013, the package of upgrades has evolved to best complement F-35, EA-18G and E-2D as they will be operating together in the air wing well into the 2040s,” Boeing said in a description of the XT/Block III aircraft.

Boeing developed the Block III jet concept to “address the strike fighter shortfall as well as to ensure the air wing has the capabilities needed to win in the 2020s and beyond,” the description said.

The new variant will feature an enhanced network capability to allow large amounts of data on and off the airplane, which would increase the ability to receive targeting information from aircraft like the F-35 Joint Strike Fighter, EA-18G Growler and the E-2D Hawkeye, according to Boeing.

The F/A-18 XT/Block III concept. Photos courtesy Boeing.

The twin-engine plane is also designed to come equipped with longer-range, low-drag, stealthy conformal fuel tanks; long-range sensors that can detect and target threats without having to depend on radar; a new advanced cockpit system to enhance situational awareness, providing the pilot with the capability to see, track and target multiple long range targets; and improved low-observable next-generation radar cross section for increased survivability, according to the company.

Weeks before being sworn in as president, Trump was vocal about an alternative to the Joint Strike Fighter, saying the “F-35 program and cost is out of control.”

“Based on the tremendous cost and cost overruns of the Lockheed Martin F-35, I have asked Boeing to price-out a comparable F-18 Super Hornet!” he tweeted Dec. 22.

The F-35 is the Pentagon’s biggest acquisition program estimated at nearly $400 billion for almost 2,500 aircraft.

After the speech Friday, Trump told reporters, “If the price doesn’t come down, we would” buy some F/A-18XTs to replace some F-35 orders. “The F-18’s a great plane and now put a stealth component onto it,” he said, according to a pool report from TIME’s White House correspondent Zeke Miller.

The military’s top brass have pointed out that older fighter jets such as the F-16 and F/A-18 will never match the F-35, an Air Force general told Military.com last month.

Brig. Gen. Scott Pleus, a former F-16 Fighting Falcon pilot who directs the F-35 Joint Strike Fighter program’s integration office for the Air Force, said even upgraded versions of the fourth-generation fighters simply can’t compete against the newer aircraft’s stealth superiority.

“The airplane is the shape of the airplane, the size is the size of the airplane,” Pleus said.

“The radar cross-section of an F-18 is the radar cross-section of an F-18 — you can’t change that,” he added. “Low observable technology, the ability to evade radar if you will, is something that has to be designed into the airplane from the very beginning.”