The House and Senate will both receive separate classified briefings on the Iran-Israel conflict Tuesday afternoon.

The briefings are expected to include National Intelligence Director Tulsi Gabbard, CIA Director John Ratcliffe, Joint Chiefs of Staff Chairman John Caine, Deputy Secretary of State Christopher Landau and Deputy Defense Secretary Steve Feinberg, sources told ABC News.

Lawmakers, especially Democrats, will be looking for answers and evidence at the briefings from the administration, specifically why President Donald Trump said there was an imminent threat and carried out U.S. strikes on Iran’s nuclear sites.

Speaker of the House Mike Johnson said late Monday he expects the House briefing to have a different "tone" in the light of the ceasefire. Though, the events overnight will likely raise even more questions from members of Congress.

-ABC News' 'Lauren Peller and Allison Pecorin

President Donald Trump and Israeli Prime Minister Benjamin Netanyahu spoke on Tuesday morning following Trump's post on social media warning Israel not to resume attacks on Iran, multiple sources familiar with the phone call told ABC News.

Trump "was exceptionally firm and direct" with Netanyahu about what needed to happen to sustain the ceasefire, one White House source said. "The prime minister understood the severity of the situation and the concerns President Trump expressed."

Netanyahu's office said Israel refrained from further attacks, but "In response to Iran's violations, the Air Force destroyed a radar array near Tehran," which would explain the reports of explosions in Iran. Israel alleged that Iran launched a barrage of missiles shortly before the ceasefire went into effect.

-ABC News' Katherine Faulders and Zoe Magee

President Donald Trump told ABC News on Tuesday morning he is "not happy" with either Israel or Iran after the opening hours of a nascent ceasefire between the two combatants were marred by reported exchanges.

Trump said Iran and Israel both "violated" the ceasefire that he announced late on Monday, in comments made as he departed the White House.

"Israel, as soon as we made the deal, they came out and dropped a boat load of bombs the likes of which I've never seen before," Trump said. "The biggest load that we've seen, I'm not happy with Israel."

"Ok, when I say now you have 12 hours, you don't go out in the first hour and just drop everything you have on them," the president added. "So, I'm not happy with him. I'm not happy with Iran either."

Trump said he was "unhappy if Israel is going out this morning because of one rocket that didn't land, that was shot perhaps by mistake, but didn't land," referring to Israeli allegations -- denied by Tehran -- that Iran fired missiles toward Israel on Tuesday after the ceasefire came into effect.

"We basically have two countries that have been fighting so long and so hard, that they don't know what the f--- they're doing," Trump said.

Asked if he believed Iran was still committed to peace, Trump replied, "I do."

-ABC News' Rachel Scott

President Donald Trump on Tuesday morning warned Israel not to violate the nascent ceasefire with Iran by launching new military strikes.

In a post to social media, the president wrote, "ISRAEL. DO NOT DROP THOSE BOMBS. IF YOU DO IT IS A MAJOR VIOLATION. BRING YOUR PILOTS HOME, NOW!"