Iran will ​avenge the blood of its martyrs, keep the Strait of Hormuz closed and attack US bases, new Supreme Leader Ayatollah Mojtaba ‌Khamenei said on Thursday in a statement read out on state television, his first remarks since succeeding his father following his assassination.

In the defiant address, Khamenei said the United States must close all its bases in the region. The strait, which runs past Iran’s coast and supplies a fifth of the world’s oil, should remain shut to put ​pressure on the enemy, he said.

“The lever of blocking the Strait of Hormuz must definitely be used,” Khamenei said of the waterway.

Ayatollah Mojtaba vowed to avenge the deaths since the start of the war, saying it would remain among his top priorities.

“A limited amount of this revenge has so far taken concrete form, but until it is fully achieved, this case will remain among our priorities,” Khamenei said in a statement read on state television.

“We will seek compensation from the enemy, and if they refuse, we will take as much of their property as we determine, and if that is not possible, we will destroy the same amount of his property,” he added.

The supreme leader also expressed gratitude to the allied armed groups across the region, including Hezbollah in Lebanon, Houthis in Yemen and allied groups in Iraq.

“We consider the countries of the Resistance Front our best friends, and the cause of resistance and the Resistance Front are an inseparable part of the values of the Islamic Revolution,” he said.

He also called on regional countries to shut down any US bases that they host.

“I recommend that they close those bases as soon as possible, because they must have realised by now that the claim of establishing security and peace by America was nothing more than a lie,” Khamenei said.

Shortly after his address, the Revolutionary Guards announced that, in keeping with his orders, they would keep the strait shut.

Two tankers were ablaze in an Iraqi port on Thursday after being hit by suspected Iranian explosive-laden boats, a step-up in attacks that have cut off oil from the Middle East. The attacks were a clear sign of defiance of US President Donald Trump, who said on Wednesday the United States had already won the war.

Images verified by Reuters as having been filmed from the shore of the port of Basra showed ships engulfed in massive orange fireballs that lit up the night sky. At least one crew member was killed in the attacks.

Hours earlier, three other ships had been struck in the Gulf. Iran’s Revolutionary Guards claimed responsibility for at least one of those attacks, on a Thai bulk carrier that was set ablaze, which the Guards said had disobeyed their orders.

Another container vessel reported being struck by an unknown projectile near the United Arab Emirates on Thursday.