Mojtaba Khamenei chosen as Iran's next supreme leader, Iranian state media reports

As the Iranians get closer to naming their next supreme leader, President Donald Trump said Sunday the new leader "is not going to last long" if the Iranians don't get his approval first.

"He’s going to have to get approval from us," Trump told ABC News' chief White House correspondent Mary Bruce. "If he doesn’t get approval from us, he’s not going to last long. We want to make sure that we don’t have to go back every 10 years, when you don’t have a president like me that’s not going to do it."

The president added, "I don’t want people to have to go back in five years and have to do the same thing again, or worse, let them have a nuclear weapon," he said.

-ABC News' Mary Bruce and Justin Fishel

Nearly 400 people have been killed in Lebanon since the start of the U.S.-Israel military operation against Iran and its proxies in the region, the Lebanese Ministry of Health said on Sunday.

Of the 394 people who have been killed in Lebanon since Feb. 28, 83 were children and 42 women, the Lebanese Ministry of Health said.

-ABC News Ghazi Balkiz

The Norwegian police said an explosion at the U.S. Embassy in Oslo early Sunday morning damaged the building, but no injuries were reported.

The incident occurred around 1 a.m. "at one of the entrances" to the embassy, the Norwegian police said in a statement.

The cause of the explosion remained under investigation.

"The police take such incidents in public spaces very seriously, and are investigating the case with large resources and high priority," the police said. "Investigations have been carried out at the scene and with both dogs, drones and helicopters looking for one or more potential perpetrators."

-ABC News' Victoria Beaule

In his Angelus prayer in St. Peter's Square on Sunday, Pope Leo warned that the conflict in Iran was fueling fear and hatred and raised concerns that it could spread further as fighting escalates.

"We raise our humble prayer to the Lord that the clamor of bombs may cease, that weapons may fall silent, and that a space for dialogue may open up in which the voice of the peoples can be heard," Leo said.

-ABC News' Joe Simonetti