Israel on Friday said it had started a "broad-scale" wave of attacks against infrastructure targets in Tehran, as Gulf cities came under renewed bombardment by Iran.
The seven-day war has now seen Iran target Israel, the Gulf states, Cyprus, Turkey and Azerbaijan, and spread to the Indian Ocean off Sri Lanka where a US submarine sank an Iranian naval ship.
On the possibility of the Iranian Kurdish forces entering Iran, Trump told Reuters on Thursday: "I think it's wonderful that they want to do that, I'd be all for it."
Two Iranian drone attacks targeted an Iranian opposition camp in Iraqi Kurdistan on Thursday, security sources said.
Iranian Kurdish militias have consulted with the United States in recent days about whether, and how, to attack Iran's security forces in the western part of the country, according to three sources with knowledge of the matter.
The Iranian Kurdish coalition of groups based on the Iran-Iraq border in the semi-autonomous region of Iraqi Kurdistan has been training to mount such an attack in hopes of weakening the country's military, as the United States and Israel pound Iranian targets with bombs and missiles.
Trump, speaking with Reuters in a telephone interview, also said the United States must have a role in deciding who will be the next leader of Iran after airstrikes killed Supreme Leader Ayatollah Ali Khamenei last week.
"We're going to have to choose that person along with Iran. We're going to have to choose that person," he said.
The attack on Iran is a major political gamble for the Republican president, with opinion polls showing little support and Americans concerned about the rise in fuel prices caused by disruption to energy supplies. Trump dismissed that concern.
Shares on Wall Street fell on Thursday, weighed by surging oil prices, as the economic impact of the campaign intensified, with countries around the world cut off from a fifth of global supplies of oil and liquefied natural gas and air transport still facing chaos and global logistics increasingly snarled.
Azerbaijan was preparing unspecified retaliatory measures on Thursday after it said four Iranian drones crossed its border and injured four people in the Nakhchivan exclave.
"We will not tolerate this unprovoked act of terror and aggression against Azerbaijan," President Ilham Aliyev told a meeting of his Security Council.
Iran, which has a significant Azeri minority, denied it targeted its neighbour.
Lebanon's Iran-backed Hezbollah militia warned Israeli residents to evacuate towns within 5 km of the border between the countries in a message posted on its Telegram channel in Hebrew early on Friday.
"Your military's aggression against Lebanese sovereignty and safe citizens, the destruction of civilian infrastructure and the expulsion campaign it is carrying out will not go unchallenged," Hezbollah said.
US defense secretary Pete Hegseth and Admiral Brad Cooper, who leads US forces in the Middle East, said during a briefing about operations that the US has enough munitions to continue its bombardment indefinitely.
"Iran is hoping that we cannot sustain this, which is a really bad miscalculation," Hegseth told reporters at Central Command headquarters in Florida. "Our munitions are full up and our will is ironclad."
The Pentagon earlier this week said the military campaign, known as Operation Epic Fury, is focused on destroying Iran's offensive missiles, missile production and navy, while not allowing Tehran to have a nuclear weapon.
Cooper said the US had hit at least 30 Iranian ships, including a large drone carrier he said was the size of a World War Two aircraft carrier.
He added B-2 bombers had in the past few hours dropped dozens of penetrator bombs targeting deeply buried ballistic missile launchers, and bombings were also targeting Iran's missile production facilities.
Iran's ballistic missile attacks had decreased by 90 per cent since the first day of the war, while drone attacks had decreased by 83 per cent in that time frame, he said.
In Iran, at least 1230 people have been killed, according to the Iranian Red Crescent Society, including 175 schoolgirls and staff killed at a primary school in Minab in the country's south on the first day of the war.
Another 77 have been killed in Lebanon, its Health Ministry says. Thousands fled southern Beirut on Thursday after Israel warned residents to leave.
