Iran has agreed to allow Pakistani vessels to pass through the embattled Strait of Hormuz, which authorities claim is a gesture of peace.

The Iranian government will open the critical waterway for 20 ships travelling under the Pakistani flag.

Under the arrangement, two ships will cross the Strait each day.

Pakistan's Foreign Minister Ishaq Dara said the move was a "welcome and constructive gesture by Iran" which "deserves appreciation".

"It is a harbinger of peace and will help usher stability in the region," Dar said in a post on X.

"This positive announcement marks a meaningful step toward peace and will strengthen our collective efforts in that direction.

"Dialogue, diplomacy, and such confidence-building measures are the only way forward."

Iran has blocked ships from entering the Strait since the US-led strikes began in late February, resulting in an oil chokepoint that has impacted supply and price on a global scale.

Millions of people have joined a fresh wave of No Kings protests across the United States, the first major rally since the US-led strikes on Iran sparked a war in the Middle East.

Around 3000 protests are taking place in cities across the country, including hundreds of thousands of people marching in the streets of New York City, Washington DC, Los Angeles, Chicago and Nashville.

Protests are also being held in solidarity in France, Italy, Portugal and Greece.

The Trump administration has condemned the No Kings rallies as "Trump Derangement Therapy Sessions" and "Hate America Rallies".

"The only people who care about these Trump Derangement Therapy Sessions are the reporters who are paid to cover them," White House spokesperson Abigal Jackson said in a statement.

Exiled Iranian Crown Prince Reza Pahlavi told a gathering of US conservatives on Saturday (Sunday AEDT) that he's ready to lead a transition away from the Islamic Republic and said when the "right moment arrives" he will call on the people of Iran to rise up.

Pahlavi spoke for nearly 30 minutes at the Conservative Political Action Conference outside Dallas where he was interrupted several times by applause and cheers.

He praised US President Donald Trump for initiating the military action against Iran's current government.

The biggest crowd reactions came when he asked the crowd if they could envision Iran turning into a friend and ally of the United States.

"Can you imagine Iran going from death to America to God bless America?" he said.

Later, the crowd erupted again when he added: "President Trump is making America great again. I intend to make Iran great again."

Iranian-backed Houthi rebels have claimed responsibility for two missile attacks on Israel as the war in the Middle East marks its one-month anniversary.

Brig Gen Yahya Saree, a military spokesman for the Houthis, issued statements on Saturday (Sunday AEDT) on the rebel group's Al-Masirah satellite television network. He said the Houthis launched two missile attacks within hours of each other.

Israel said it intercepted the first missile. It did not immediately comment on whether it intercepted any projectiles from Yemen in the second attack.

The attacks came after Saree signaled in a vague statement on Friday that the rebels would join the war.

It is the first time Israel has faced fire from Yemen since the start of the conflict last month. Houthi attacks on vessels during the Israel-Hamas war upended shipping in the Red Sea.

Foreign ministers from Saudi Arabia, Turkey and Egypt will attend talks in Islamabad on Sunday (Monday AEDT) aimed at ending the war, Pakistan's Foreign Minister Ishaq Dar has said.