Iran live updates: White House calls on other nations to secure Strait of Hormuz

As President Donald Trump continues to urge countries to assist with the escalating crisis in the Strait of Hormuz, he reportedly issued a warning to NATO on Sunday, saying it will be "very bad" for the global alliance if they do not respond or comply.

"If there's no response or if it's a negative response, I think it will be very bad for the future of NATO," he reportedly told the Financial Times in a phone interview.

The president has spent the weekend insisting that because other countries, particularly Europe and China, are dependent on the oil that flows through the Strait, they should be responsible for assisting with the escalating oil crisis.

"It's only appropriate that people who are the beneficiaries of the Strait will help to make sure that nothing bad happens there," Trump said.

The president also floated postponing his trip to Beijing to meet with Chinese President Xi Jinping, which a White House official previously told ABC is currently scheduled for March 31 to April 2. He did not say how long he may delay the trip.

Trump told the FT that he would "like to know" if China would help with unblocking the Strait of Hormuz before the summit takes place.

-ABC News' Emily Chang and Meghan Mistry

Pope Leo XIV demanded a ceasefire in the Middle East on Sunday in his strongest comments to date, directly addressing the leaders who launched the war in Iran.

"On behalf of the Christians of the Middle East and all women and men of good will, I appeal to those responsible for this conflict," Leo said. "Cease fire so that avenues for dialogue may be reopened. Violence can never lead to the justice, stability, and peace that the people are waiting for."

Leo didn't cite the United States or Israel by name in his comments at the end of his Sunday noon blessing. But history's first U.S. pope mentioned the attacks that targeted a school, an apparent reference to the missile strike on an elementary school in Iran in the opening days of the war that killed over 165 people, many of them children.

U.S. officials have said outdated intelligence likely led to the United States launching the strike, and that an investigation is ongoing.

The Vatican has highlighted the carnage of the Minab strike, running an aerial photo of the mass grave being dug for the young victims on the March 6 front page of its official newspaper, L'Osservatore Romano, under the headline "The Face of War."

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U.K. Prime Minister Sir Keir Starmer spoke with President Donald Trump Sunday about the ongoing situation in the Strait of Hormuz, according to a spokesperson for the prime minister's office.

"The leaders discussed the ongoing situation in the Middle East and the importance of reopening the Strait of Hormuz to end the disruption to global shipping, which is driving up costs worldwide," the spokesperson said.

"The Prime Minister also expressed his condolences for the American service personnel who have lost their lives during the conflict," according to the spokesperson, who added that the leaders "agreed to keep in touch."

The spokesperson also said that Starmer had spoken Sunday with Canadian Prime Minister Mark Carney and "discussed the situation in the Middle East, including the impact of the continued closure of the Strait of Hormuz on international shipping."

"They agreed to discuss the ongoing conflict further in their meeting tomorrow, among other bilateral issues," the spokesperson said.

President Trump on Saturday called for other countries, including the U.K., to step in and assist with the escalating crisis in the Strait of Hormuz.

-ABC News' Mike Trew

Iraq's Security Media Cell, an office of the prime minister, said that five rockets targeted Baghdad airport Sunday, injuring five people.

"At exactly 19:00 this evening, Baghdad International Airport and its surroundings came under attack by 5 rockets, resulting in injuries to 4 airport staff and security personnel, in addition to an engineer, with varying degrees of wounds," the statement said.

The rockets struck numerous areas including on the grounds of the Baghdad Central Prison, which is near the former American base Camp Victory on the airport grounds, according to the statement.

"Competent authorities have begun taking the necessary legal measures, alongside tightening security procedures around the targeted areas," the statement said.

-ABC News' Victoria Beaule