GEOFF BENNETT: Tonight, the U.S.

is launching the fourth night of strikes in a row, and it's relaunching its naval blockade of all Iranian ports, its most formal step toward resuming full-scale war with Iran.

President Trump says the move is designed to starve Iran's regime of oil revenue.

Iran in return continues to attack ships and U.S.

allies in the Gulf and refuses to reopen the Strait of Hormuz.

Nick Schifrin has more.

NICK SCHIFRIN: Tonight, U.S.

warships are once again blockading Iranian ports.

The U.S.

will prevent all Iranian ships or ships doing business with Iran from either departing or arriving in the ports where Iran exports oil and imports essential goods.

DONALD TRUMP, President of the United States: I gave them a chance.

NICK SCHIFRIN: It's the most formal step President Trump has taken toward resuming the war.

But, today, during a meeting with Iraq's new prime minister, he simultaneously scrapped a different plan.

DONALD TRUMP: Because I don't think anybody should be able to charge a fee for the strait.

NICK SCHIFRIN: The president had raised taxing all cargo passing through the Strait of Hormuz with what he called a 20 percent reimbursement for U.S.

military efforts.

Today, he said Gulf allies opposed that and instead offered him a deal.

DONALD TRUMP: They're going to be making massive investments into the United States, and I like that much better.

NICK SCHIFRIN: It all comes after another night of fire between the U.S.

and Iran.

The U.S.

military says it targeted Iranian air defense, missiles, drones, and maritime capabilities at about half-a-dozen sites, including Iran's main Strait of Hormuz port, Qeshm island.

Iran responded with strikes of its own, targeting several U.S.

allies across the Gulf, including ballistic missiles that appeared to hit Jordan's King Faisal Air Base.

More attacks are coming, vowed Iranian President today Masoud Pezeshkian.

MASOUD PEZESHKIAN, Iranian President (through translator): The people who wanted to turn Iran to pieces, what have they reached?

We respond in action and protect what we believe in, every inch of our soil.

NICK SCHIFRIN: Iran also struck two Emirati tankers that it said was transiting through an unapproved route.

The strikes killed one mariner from India, sparking Indian government outrage.

RANDHIR JAISWAL, Spokesperson, Indian Ministry of External Affairs: We conveyed our strongest protest with the Iranian side on this particular matter, that these attacks, which we condemn, must stop at the earliest.

NICK SCHIFRIN: But, today, there is instead talk of more war, including a threat delivered by Israeli Prime Minister Benjamin Netanyahu in the city that reportedly holds Israel's lone nuclear reactor.

BENJAMIN NETANYAHU, Israeli Prime Minister (through translator): Do not count on it being quiet if you attack us.

Do not count on a rerun, because it will not be a rerun.

And that was already powerful enough.

This will be a different event.

Much more powerful.

NICK SCHIFRIN: The antipathy is equal opportunity.

Today, Iran's Parliament met publicly for the first time in four months.

And lawmakers chanted "Death to America."

And Iran's military maintains its choke hold over the Strait of Hormuz.

Today, the price of oil spiked again, suggesting even traders are not expecting the strait to return to normal any time soon.