President Trump said he believes that Kim Jong Un will begin dismantling North Korea’s nuclear arsenal “virtually immediately” after the two leaders met in a historic summit in Singapore.​

​“I just think that we are now, we are going to start the process of denuclearization of North Korea, and I believe that he’s going back and will start it virtually immediately — and he’s already indicated that and you look at what he’s done,” Trump told Fox News’ Sean Hannity, referring to how Kim destroyed a missile testing site earlier this month.

Trump and Kim signed a document that calls for ​Pyongyang to work “toward complete denuclearization of the Korean Peninsula.​”​

​The president said he and Kim “got along from the beginning” and the North Korean leader realized that he must get rid of his nuclear weapons.​

​“His country has to be de-nuked and he understood that, he fully understood that, he didn’t fight it,” Trump said.

​He also credited the fiery rhetoric unleashed by the two leaders over the past year and a half with propelling them to their landmark Singapore summit — the first-ever meeting between a sitting US president and a North Korean leader.​

“So I think the rhetoric, I hated to do it, sometimes I felt foolish doing it, but we had no choice,” he said.

Asked what happens next, Trump said: “I think he’s gone back to get this done. He wants to get it done.”

The full interview will air ​on “Hannity” at 9 p.m. Tuesday.