French President Emmanuel Macron said Tuesday that the United States and Israel's military operations in Iran were conducted "outside international law", but placed primary blame on the Islamic republic.

"The United States of America and Israel decided to launch military operations, conducted outside international law, which we cannot approve of," said Macron.

US and Israeli strikes pummeled targets across Tehran on Tuesday, as President Donald Trump warned it was "too late" for Iran to seek talks to escape a war now in its fourth day.

Drones and missiles crashed into oil facilities and US embassies in the Gulf as the Islamic republic retaliated, and Israel pushed troops deeper into Lebanon to battle the Tehran-backed militia Hezbollah after it entered the fray.

New strikes were reported Tuesday across the Middle East, including Israeli bombardment on Lebanon and a drone attack on the U.S. embassy in Saudi Arabia's capital Riyadh.

The conflict started with U.S. and Israeli strikes on Iran over the weekend, which sparked retaliatory Iranian attacks across the region, and showed no sign of abating as it entered its fourth day.

The Palestinian Islamic Jihad’s armed wing said on Monday that its commander in Lebanon was killed in Israeli strikes on Beirut’s southern suburbs.

In a statement, the Quds Brigades said Adham Adnan al-Othman, the head of the armed wing in Lebanon, was killed "as a result of the treacherous Zionist aggression that targeted the southern suburbs of Beirut, at dawn on Monday".

The war launched by the United States and Israel against Iran spread across the Middle East and beyond on Monday, with Lebanon's Hezbollah entering the fray and a British air base in Cyprus targeted.

Iran’s army said Monday it targeted US Ali Al Salem air base in Kuwait as well as vessels in the Indian ocean after the killing of the Islamic republic’s supreme leader in U.S. and Israeli strikes.

"Missile units of the army’s ground and naval forces operating from various locations targeted the U.S. Ali Al Salem air base in Kuwait as well as enemy vessels in the northern Indian Ocean over the past hours," the army said in a statement.

Israel and Hezbollah traded fire on Monday, while President Donald Trump vowed to avenge the deaths of U.S. service members and said the war with Iran could last for weeks.

The European Union has warned of the cost to the Middle East of a long war, and said it was reinforcing its naval mission in the Red Sea.

The U.S. military on Sunday said three service members have been killed and five seriously wounded in the operation against Iran -- the first casualties of any kind announced on the U.S. side.

The death toll from an Iranian missile attack Sunday in the Israeli city of Beit Shemesh rose to at least nine people, first responders said, in the deadliest strike in the country since the war began.

The Magen David Adom emergency service said: "In the Beit Shemesh area, MDA EMTs and paramedics have pronounced the deaths of nine" people, as well as 28 others injured, with police saying it was a direct hit on a building.

U.S. President Donald Trump on Sunday said he would "be talking" to Iranian leaders but was vague on the timing and noted that much of the country's leadership was dead.