WASHINGTON — President Trump said Tuesday that he’s poised to order a “big hit” on Iran if nuclear negotiations falter.

Trump said he was “an hour away” from scrapping his six-week cease-fire and launching a blitz Tuesday before deciding to give peace a chance — for now.

“We may have to give them another big hit. I’m not sure yet. You’ll know very soon,” Trump told reporters on the White House lawn as he showed off construction on the mansion’s ballroom.

“I mean, I’m saying two or three days, maybe Friday, Saturday, Sunday, something, maybe early next week, a limited period of time.”

He added: “I’m not going to let the world be blown up on my watch.”

Trump has vacillated for weeks between touting progress in talks with Iranian negotiators and threats to resume the bombing — at points fuming about what he says is Iranian backtracking.

He said that he decided to stall a resumption of the war because of outreach from Gulf Arab allies.

“They had heard I made the decision and said, ‘Sir, could you give us a couple of more days, because we think they’re being reasonable,’” he said.

But what progress has been made remains unclear — as Iranian officials added incendiary new provisions to their latest public peace offer, which again demands that the Islamic Republic be treated as the war’s winner.

In addition to demanding reparations and an end to sanctions, Iran is seeking sovereignty over the Strait of Hormuz and the withdrawal of US troops from neighboring countries, with no nuclear concessions.

Trump has made clear that his primary goal is Iran’s commitment not to seek nuclear weapons, including its relinquishment of enriched uranium that could be enriched to bomb-grade in a short period of time.

The president accused Democrats of undermining his negotiating position.

“I’m in the middle of a negotiation, I’m saying you cannot have a nuclear weapon, and it comes over the wire that the Democrats want to stop Trump from further negotiations,” he griped.

“They want to stop Trump from, if he has to, giving them another slap.”

Vice President JD Vance, who led a US delegation to Pakistan for 21-hour marathon overnight peace talks last month, told reporters Tuesday afternoon that Trump doesn’t want to restart the war.

“We think we’ve made a lot of progress. We think the Iranians want to make a deal,” Vance said at a press briefing.

“[Trump] has asked us to negotiate in good faith, and that’s exactly what we’ve done, so we’re in a pretty good spot here, but there’s an option B, and the option B is that we can restart the military campaign.”

“That’s not what the president wants,” Vance said.

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“And I don’t think it’s what the Iranians want either.”

Vance disclosed, however, that Iranian negotiators haven’t raised Russian President Vladimir Putin’s offer to take possession of Iran’s enriched uranium and seem to have ruled out the face-saving off-ramp.

“The Iranians have not raised it,” Vance disclosed. “My sense is that’s not something the Iranians would be particularly excited about, and I know the president isn’t particularly excited about it either. But who knows.”

Trump has claimed Iran, at times, agreed to relinquish its uranium to the US, but Iranian officials have denied it.

Vance, a longtime critic of open-ended foreign interventions, tried to reassure the public that “this is not going to be the sort of thing that lasts forever.”

“We have to remember that [of the] 11 weeks, a big chunk of that has been a ceasefire. This is not a forever war,” Vance said. 

“We’re going to take care of business and come home.”

The head of US Central Command said Tuesday that American troops are ready to resume strikes if ordered, likening them to a football team poised to snap into action.

“The US military, in the meantime, is fully postured in a three-point stance, ready to go a number of different directions as directed,” Admiral Brad Cooper told the House Armed Services Committee.

“The implementation of blockade is highly effective and is being used as a very strong lever in diplomatic negotiations, and those diplomatic negotiations, governed by policy, will take the way ahead,” Cooper said.

Central Command says 89 Iran-linked commercial vessels have been “redirected to ensure compliance” with Trump’s blockade, which started April 13.

Tehran revealed its latest counteroffer Tuesday — which remained almost entirely unchanged from prior public positions — including the right to enrich uranium and maintain a “peaceful” nuclear program – two items that are unacceptable to Trump.

The full list included reparations from the US, the release of frozen Iranian assets, the lifting of all “unilateral sanctions” and UN Security Council resolutions, an end to the blockade and withdrawal of US forces “from areas surrounding the Islamic Republic,” Iranian state media reported.

It also demanded an end to all combat operations associated with the war, including Israeli action against Hezbollah in Lebanon.

Some experts said the lack of movement indicates Iran is willing to keep testing Trump.

But if they continue their refusal to budge, Cooper said he is “prepared to execute a broad range of contingencies.”

“Where we sit today — we’re executing a blockade, and we’re prepared for further direction, depending on how negotiations go, so the state of preparedness remains at its highest level,” he said.

The conflict is in its third month but Trump said an end is likely “very soon.”

“One way or the other, whether it’s military or an agreement, that’ll start opening up very soon,” he said.