WASHINGTON — The U.S. and Israeli war against Iran entered its ninth day Sunday with no clear path toward de-escalation, as the U.S. announced a seventh American service member had been killed and Iranian state TV reported the selection of Supreme Leader Ayatollah Ali Khamenei’s son as his successor.

Meanwhile, the price of oil surpassed $100 a barrel for the first time in 3½ years.

President Trump said deploying American ground troops to the Middle East remains under consideration and Iran’s foreign minister rejected calls for a ceasefire.

Trump said last week that Mojtaba Khamenei would be an “unacceptable” choice to replace his father, the 86-year-old leader who was killed on the first day of U.S. and Israeli attacks. The clerical body in charge of choosing Iran’s next supreme leader selected him anyway, state TV reported Sunday.

The younger Khamenei, a 56-year-old Shiite cleric, has never held government office, but has long been a quiet force within his father’s inner circle. As supreme leader, he will play a central role in deciding Iran’s war strategy moving forward, with the powerful paramilitary Islamic Revolutionary Guard Corps answering to him.

The White House did not immediately respond to a request for comment on his selection.

Speaking to reporters on Air Force One on Saturday, Trump declined to rule out the possibility of sending U.S. forces inside Iran, saying it could “possibly happen” as the conflict intensifies.

“There would have to be a very good reason,” Trump said. “I would say if we ever did that they would be so decimated that they wouldn’t be able to fight at the ground level.”

His remarks came ahead of another relentless day of bombings in Iran, and as desalination plants critical to civilian water supplies in the arid region came under attack on both sides of the conflict.

The United States military on Sunday announced that an American service member died Saturday night of injuries sustained March 1 in Saudi Arabia during Iran’s “initial attacks” on U.S. allies and facilities across the region, in response to U.S. and Israeli strikes. The service member was not immediately identified, pending notification of family.

In addition to the seven U.S. service members killed in the war, a National Guard soldier died Friday of a “health-related incident” in Kuwait, where he had been deployed, the military said. The cause of death was under review.

Other deaths were also reported in the region. Israel reported two of its soldiers were killed in fighting in southern Lebanon — its first military deaths of the war — while Saudi Arabia reported two people were killed and 12 wounded by a military projectile that fell in a residential area of Al Kharj.

The death toll in Iran has been difficult to nail down, but Iran’s ambassador to the United Nations on Friday put the number at more than 1,300.

Iran has said it is prepared to continue fighting the war despite sustaining heavy losses and would be ready to fight American ground troops if they set foot in the country.

“We have very brave soldiers who are waiting for any enemy who enters into our soil to fight with them, and to kill them and destroy them,” Iran’s foreign minister, Abbas Araghchi, said in an interview with NBC’s “Meet the Press” on Sunday.

Araghchi added that Iran is not considering a ceasefire at this time. He said the United States and Israel would first need to explain “why they started this aggression and then guarantee there would be a permanent end of the war.”

“Unless we get to that, I think we need to continue fighting for the sake of our people and our security,” he said.

Araghchi also pushed back on Trump’s demand last week that the president be involved in determining Iran’s future leadership as a condition to ending the conflict.

“We allow nobody to interfere in our domestic affairs. This is up to the Iranian people to elect their new leader,” Araghchi said. “It’s only the business of the Iranian people, and nobody else’s business.”

In addition to mounting deaths and widespread destruction, the economic toll of the war has also continued to rise, particularly in energy markets — with oil prices jumping above $100 a barrel on Sunday.

“If the war continues like this, there will be neither a way to sell oil nor have the ability to produce it,” Iran’s parliament Speaker Mohammad Bagher Ghalibaf said in a social media post Sunday. He added that the war would affect not just the U.S., but also the rest of the world “due to [Israeli Prime Minister Benjamin] Netanyahu’s delusions.”

Israeli strikes Sunday hit an oil storage facility in Tehran, marking what appears to be the first time a civil industrial facility has been targeted in the war. Black smoke billowed over the Iranian capital, with officials there warning of the hazardous health effects for residents.

“By targeting fuel depots, the aggressors are releasing hazardous materials and toxic substances into the air, poisoning civilians, devastating the environment, and endangering lives on a massive scale,” Iran’s Foreign Ministry spokesperson Esmaeil Baqaei said on X.

U.S. Energy Secretary Chris Wright said Sunday that there’s a “fear premium in the marketplace” and sought to assure Americans that the soaring oil prices are a short-term problem.

“We never know exactly the time frame of this,” Wright said in an interview with CNN’s “State of the Union.” “But in the worst case, this is a weeks, this is not a months, thing.”

White House Press Secretary Karoline Leavitt echoed the same message in an interview with Fox News’ “Sunday Morning Futures,” calling the rising gas prices a “short-term disruption.”

“Ultimately taking out the rogue Iranian regime is going to be a good thing for the oil industry,” Leavitt said. “Those prices are going to come back down just like they have over the course of the past year, because of President Trump’s American energy dominance agenda.”

The strike on the oil storage facility came as Netanyahu promised “many surprises” for the next phase of the conflict.

Israel also claimed Sunday to have destroyed the Tehran headquarters of the Revolutionary Guard air force, which it said operated Iran’s “ballistic missile command, unmanned aerial vehicle (UAV) array, and other air force units.” It also said it had killed five top commanders in the Revolutionary Guard who were “hiding in a civilian hotel” in central Beirut, Lebanon.

Crucial civilian infrastructure also came under attack, on both sides of the conflict.

Bahrain denounced what it said was an Iranian attack on one of its desalination plants — facilities that supply water to millions of people in the parched deserts of the Persian Gulf. Araghchi said a U.S. airstrike had damaged an Iranian desalination plan on Qeshm Island first.

“Attacking Iran’s infrastructure is a dangerous move with grave consequences. The U.S. set this precedent, not Iran,” Araghchi wrote on X.

The United States has also come under scrutiny after evidence suggested that an American strike was probably responsible for an explosion at an Iranian elementary school that killed more than 165 people, most of them children.

Trump administration officials have said that the matter is under investigation and that no determination has been made as to who was responsible for the strike. But on Saturday, Trump said Iran was to blame for the explosion.

“It was done by Iran,” he told reporters. “They’re very inaccurate, as you know, with their munitions. They have no accuracy whatsoever. It was done by Iran.”

Asked Sunday whether Iran had any evidence that the strike was conducted by the Americans, Araghchi said that it had to have been either the U.S. or Israeli military and that Trump’s suggestion that Iran was responsible for the attack was “funny.”

“It is our school, these are our students and our girls, and they are attacked by an American fighter, a jet fighter, and they have been killed. Why [is] Iran responsible?” Araghchi said.

Other world leaders and nations have called for a halt to fighting and added their own estimates to its toll.

Lebanon said more than half a million people have been displaced by the fighting between Israel and Hezbollah.

French President Emmanuel Macron said he had spoken with Iranian President Masoud Pezeshkian on Sunday, and urged him to stop strikes in the region. Macron is the first Western leader to speak with Pezeshkian since the war began, the Associated Press reported.

Pope Leo XIV wrote on X on Sunday that reports out of Iran and the wider Middle East “continue to cause deep dismay and raise the fear that the conflict will expand, and that other countries in the region, including dear Lebanon, may once again sink into instability.”

He asked the world to pray “for the roar of bombs to cease, weapons to fall silent, and space to open for dialogue, in which people’s voices may be heard.”