Political leaders and many Americans breathed a sigh of relief on Tuesday evening, after Donald Trump announced a provisional ceasefire deal following threats to destroy Iran’s “whole civilization” if Tehran failed to reopen the strait of Hormuz by a self-imposed deadline.

The announcement of the agreement, mediated by Pakistan, came roughly 90 minutes before the 8pm ET deadline by which Trump pledged to bomb Iran’s power plants and bridges in a move legal and military scholars said would be considered a war crime.

“Subject to the Islamic Republic of Iran agreeing to the COMPLETE, IMMEDIATE, and SAFE OPENING of the Strait of Hormuz, I agree to suspend the bombing and attack of Iran for a period of two weeks,” Trump wrote in a post on Tuesday evening.

Iran’s foreign minister said the passage through the strait of Hormuz would be allowed for the next two weeks under Iranian military management.

Trump had earlier warned that “a whole civilization will die tonight, never to be brought back again” if Iran failed to allow commercial shipping to pass safely through the strai. The president’s comments were swiftly condemned by Democrats, longtime supporters who have broken with Trump over the war, and Pope Leo, the first American pontiff.

“I’m glad Trump backed off and is desperately searching for any sort of exit ramp from his ridiculous bluster,” Chuck Schumer, the Senate Democratic leader, said on Tuesday night, reacting to the news of a two-weak provisional ceasefire. Earlier, Schumer called Trump an “extremely sick person” waging a “wanton war of choice”.

Following his increasingly bellicose threats of imminent demolitions, dozens of House Democrats, including the former speaker Nancy Pelosi, had called for Trump’s removal, either through impeachment or by invoking the 25th amendment, a constitutional process to declare a sitting president no longer capable of fulfilling his duties. Former Maga allies turned critics, including former congresswoman Marjorie Taylor Greene and the far-right media personality Candace Owens, denounced Trump’s threats as “evil” and “madness”.

Several Republicans cheered the president’s decision, casting it as shrewd and tactical.

“Excellent news,” Senator Rick Scott of Florida said. “This is a strong first step toward holding Iran accountable and what happens when you have a leader who puts peace through strength over chaos and weak appeasement policies.”

Senator Lindsey Graham, one of the chamber’s loudest and most aggressive Iran hawks, said on Tuesday evening he shared the hope that “we can end the reign of terror of the Iranian regime through diplomacy”.

But he added: “We must remember that the strait of Hormuz was attacked by Iran after the start of the war, destroying freedom of navigation. Going forward, it is imperative Iran is not rewarded for this hostile act against the world.”

Congressman Dan Crenshaw, a Texas Republican who has a history of breaking with Trump, chided the president’s many critics for “pearl-clutching” over his bombastic rhetoric and for once again taking the president “literally”.

“Take a breath,” Crenshaw wrote on X after the president’s announcement, adding: “President Trump speaks in terms of POWER, which is the only language our adversaries understand. Carefully worded diplomatic statements make the UN feel nice and cozy but also don’t get anything done.”