Facing intense blowback from his nationalist base, President Trump on Thursday doubled down on his vow to build a wall on the Mexican border — and said there would be no citizenship or amnesty for the 800,000 Dreamers in the US.

“We have to have the wall. if we don’t have the wall we’re doing nothing,” the president said as he arrived in Florida to inspect damage from Hurricane Irma.

“At some point [Democrats] cannot obstruct the wall. To me it is vital. If I don’t get the wall, then we will become the obstructionist,” he added, in an apparent warning to Democrats that the GOP would not cut any deals unless the wall is funded.

“We have to have an understanding that whether it’s in the budget or some other vehicle, in a fairly short period of time, the wall will be funded. Otherwise, we’re not doing any deal,” he said in remarks that aimed to reassure his base.

Trump also said that people protected from deportation by the Obama administration’s Deferred Action for Childhood Arrivals (DACA) program would not be granted citizenship or amnesty.

“We’re not looking at citizenship or amnesty. We’re looking at allowing people to stay here. We’re talking about taking care of people, people that were brought here, people that have done a good job and were not brought here of their own volition, but importantly, what we want, we have to have a wall,” he said.

Senate Minority Leader Chuck Schumer and House Minority Leader Nancy Pelosi announced after dining with Trump at the White House Wednesday that they had cut a deal with the president to keep DACA protections in place — and that the agreement did not include building a wall.

Their announcement ignited a raging firestorm among immigration hard-liners — with lawmakers and pundits slamming the president on social media, conservative websites like Breitbart and cable news.

Trump and two administration spokeswomen argued that the wall remained a priority, saying it would be built and paid for at some point down the road.

Asked at the airport in Fort Myers if he was concerned about criticism from the GOP, the president painted a rosy picture of his relationship with his own party, which has been strained since he made a deal with “Chuck and Nancy,” as he called them, last week on Hurricane Harvey aid and raising the debt ceiling.

“We’re doing it in conjunction with the Republicans. We have a very, very good relationship with a lot of people, a lot of people want this to happen, they expect it to happen, and we’ll see if it happens. But we’ll only do it if we get extreme security,” he said.

Spokeswoman Lindsay Walters told reporters aboard Air Force One that Trump had spoken to House Speaker Paul Ryan and Senate Majority Leader Mitch McConnell earlier Thursday.

But Iowa GOP Rep. Steve King apparently wasn’t convinced, telling CNN before Trump spoke that the president seems more interested in keeping Hillary Clinton’s campaign promises than his own.

“So I think something is going to have to get reversed here with this president’s policy or it will just blow up his base. I mean this was a straight up promise all the way through his campaign,” King said on “New Day.”

“I don’t think it’s unclear to anybody what those campaign promises were, but it looks to me like he’s preparing to keep Hillary Clinton’s promise rather than his own.”