Donald Trump is getting “nuttier and nuttier,” according to those within the tycoon’s presidential campaign, who say they are increasingly frustrated by his outrageous comments and behavior.

The Republican candidate has been engaged in a prolonged war of words with Khizr and Ghazala Khan — whose son, a US Army officer, was killed in Iraq in 2004 — which many inside the presidential campaign see as, at the very least, a total distraction.

“I did not think he’d be great in a general election, and thought there’d be episodes of paranoia/irrationality, but this is surprising for me,” one Trump operative told The Post.

“Trump is getting nuttier and nuttier,” the person added.

Trump loves crying baby, then kicks him out of rally:

Campaign chairman Paul Manafort and other staffers “feel like they are wasting their time,” CNN reported Wednesday.

Campaign aides wish Trump were spending more time talking about public policy and aiming his fire at Hillary Clinton.

And CNBC’s John Harwood quoted a source as saying: “Manafort not challenging Trump anymore. Mailing it in. Staff suicidal.”

But Trump campaign spokesman Jason Miller insisted the campaign is going strong: “[T]he idea that Paul Manafort is mailing it in is completely erroneous. Our campaign just finished up our strongest month of fundraising to date, we’re adding talented and experienced staffers on a daily basis and Mr. Trump’s turning out bigger, more enthusiastic crowds than Hillary Clinton ever could.”

Meanwhile, Republican National Committee Chair Reince Priebus is “apoplectic” at Trump because the nominee has refused to back House Speaker Paul Ryan in his primary battle, NBC reported.

“I like Paul, but these are horrible times for our country,” Trump told the Washington Post in an interview Tuesday.

“We need very strong leadership. We need very, very strong leadership. And I’m just not quite there yet. I’m not quite there yet.”

Priebus reportedly expressed his displeasure with the Republican presidential candidate directly to Trump staffers.