The meeting was about hurricane preparations, but President Donald Trump unleashed a storm of his own, commandeering the gathering and droning on about his negotiating skills to cut the cost for a new Air Force One, his upcoming summit with the North Korean leader and the California governor race, according to a report on Thursday.

Trump let loose with a torrent of comments during a 40-minute, closed-door briefing session at Federal Emergency Management Agency headquarters on Wednesday.

“It’s an interesting journey. It’s called the land of the unknown — who knows? We’ll maybe make a deal. Maybe not. As I say to everybody, are you going to make a deal?” Trump said about his June 12 meeting in Singapore with Kim Jong Un, the Washington Post reported. “Maybe and maybe not. Who knows?”

He interrupted Deputy Secretary of Defense Patrick Shanahan to complain about how the US was getting ripped off on ships and planes because the “ordering process is so bad. … It’s not a competitive bid.”

​He segued to boasting about how he worked out a deal with Boeing on Air Force One.​

“We saved $1.6 billion on Air Force One,” he said. “Can you believe it? I got involved in the negotiations. The press refuses to report that, but that’s OK. . . . People were really surprised.”

Military officials haven’t been able to explain that figure, the newspaper reported.

Trump then blamed the military for buying unnecessary equipment, referring to new technology.

“Part of it is, they want to have all new. Instead of having the system that throws the aircraft off the [ship], which was always steam,” he said​, according to a tape of his comments obtained by the Washington Post. “They now have magnets. They’re using magnets instead of steam. . . . They spent hundreds of millions of dollars, I’m hearing not great things about it. It’s frankly ridiculous.”

Turning to California, Trump crowed about backing Republican John Cox who will face off against Democrat Gavin Newsom for governor in November.

“I endorsed him,” he said of Cox. “He really has been a very good candidate. I watched him last night. . . . We won every seat that I endorsed. The ones we didn’t give, they didn’t do too well, as you probably know.”

He did bring up hurricanes, briefly mentioning Hurricane Maria by thanking Florida Gov. Rick Scott, a Republican, for assisting Puerto Rico where hundreds of thousands are still without power.

He noted that the ​US territory’s ​power company was in “bankruptcy prior to the hurricane.”

​But he didn’t mention the death toll, which a Harvard study estimated to be more than 4,500.

The Puerto Rico Department of Health​ said ​there were an additional 1,400 deaths in the months after Maria, compared to the same time period the year before.