Iran live updates: Trump says without ceasefire, there will be 'one big glow coming out of Iran'

Secretary of State Marco Rubio told reporters the administration expected a response from the Iranian regime on Friday, but that "only stupid countries" wouldn't respond to fire with fire when facing attacks like the U.S. did in the Strait of Hormuz.

"The red line is clear: They threaten Americans, they're gonna get blown up," Rubio told reporters Friday.

"If you fire at a U.S. Navy ship, what are we supposed to do?" Rubio said. "Of course we fired back on them. They were shooting at us. That's what I would expect to do. Only stupid countries don't shoot back when you're shot at," Rubio said. "And we're not a stupid country."

On talks with the regime, Rubio said "we should know something today" and "the hope is it's something that it can put us into a serious process of negotiation."

"We're expecting a response from them today, at some point. We have not received that yet as-in the last in the last hour, but perhaps that will come. Their system is still highly fractured and a bit dysfunctional as well, so that may be serving as an impediment," Rubio said. "I hope it's a serious offer. I really do."

As the U.S. struck Iran again in what the president described to Rachel Scott as a "love tap," standing in the foundation of the drained Lincoln Memorial Reflecting Pool on Thursday, he offered a much starker picture of what the world would see if the ceasefire between the U.S. and Iran comes to an end.

"If there's no ceasefire, you're not going to have to know. You're just going to have to look at one big glow coming out of Iran. And they better sign their agreement fast," Trump said, when pressed on what the strikes meant for the ceasefire with Iran.

"But they have to understand if it doesn't get signed, they're going to have a lot of pain. They're going to have a lot of pain," Trump added. "They want to sign it. I will tell you, they want to sign it a lot more than I do."

It's not the first time the president has described the war in such severe terms.

In fact, it was exactly one month to the day on Thursday since Trump threatened that a "whole civilization will die tonight, never to be brought back again," before announcing a then-two-week ceasefire with Iran. The president says it remains in place today.

President Donald Trump, speaking to reporters on Thursday, said the U.S. military struck Iranian targets earlier after "they trifled with us," but that the fragile ceasefire is still on.

"They trifled with us today. We blew them away," Trump said.

Earlier, U.S. Central Command said three U.S. Navy destroyers were crossing the Strait of Hormuz when they came under fire from Iranian missiles and drones, and the U.S. launched "self-defense" strikes in response.

"They should not have done that today," Trump said. "We thought they might. We didn't know, but we were prepared. They shot missiles. Every missile was knocked down, every drone was knocked down, and the people that shot it are no longer with us."

Trump made his comments during an impromptu visit to the Lincoln Memorial Reflecting Pool, which is undergoing renovations.

Trump also said that the proposal between the two countries is "more than a one-page offer."

Sources have told ABC News that a major sticking point remains the future of Iran's nuclear weapons program, and the president vowed not to let the country obtain or develop one.

Trump also said that a deal could happen "any day" but it also "might not happen" -- a sentiment he's repeated several times throughout the course of the war.

-ABC News' Meg Mistry, Rachel Scott, Karen Travers and Nicholas Kerr

President Donald Trump reiterated his threat for Iran to agree to make a deal to restart negotiations to end the war -- or face attacks again -- after the U.S. military said Iran fired "unprovoked" attacks on three U.S. Naval destroyers in the Strait of Hormuz.

"[J]ust like we knocked them out again today, we'll knock them out a lot harder, and a lot more violently, in the future, if they don't get their Deal signed, FAST!" Trump said on social media.

Trump said the three U.S. warships "transited, very successfully, out of the Strait of Hormuz, under fire."

"There was no damage done to the three Destroyers, but great damage done to the Iranian attackers," Trump said.

The president said Iran attacked the warships with missiles and drones, which the U.S. destroyed.

-ABC News' Meghan Mistry