Protesters on Thursday in the northern city of Gorgan poured into the streets in large numbers, chanting pro-Pahlavi slogans.
Same chants were heard in the holy city of Mashhad in northeastern Iran.
"This is the final battle, Pahlavi will return," protesters were heard chanting in Mashhad on Thursday night.
US President Donald Trump suggested it would not be appropriate to meet US-based exiled Iranian Prince Reza Pahlavi in an interview with podcaster Hugh Hewitt.
"Would you meet with Crown Prince Pahlavi, who is the heir to the constitutional monarchy. He doesn't want to rule. He would be a, you know, symbolic ruler like King Charles," Hewitt asked.
"Well, I've watched him, and he seems like a nice person, but I'm not sure that it would be appropriate at this point to do that as President," Trump responded. "I think that we should let everybody go out there and we see who emerges. I'm not sure necessarily that it would be an appropriate thing to do."
"We certainly stand by anybody who is engaged in peaceful protests, anybody who is trying to exert their rights of free association and to have their voices heard," US Vice President JD Vance told reporters on Thursday.
"Obviously, the Iranian regime has a lot of problems, as the President of the United States has said, the smartest thing for them to have done, it was true two months ago, it's true today, is for them to actually have a real negotiation with the United States about what we need to see when it comes to their nuclear program," Vance added.
"I'll let the President speak to what we're going to do in the future. But we certainly stand with anybody across the world, including the Iranian people, who are advocating for their rights."

US President Donald Trump warned Iran’s authorities against killing protesters, while praising Iranians as “brave people” amid nationwide protests on Thursday.
“They know, and they’ve been told very strongly… that if they do that, they’re going to have to pay hell,” Trump said.
Addressing the Iranian people, Trump said: “You should feel strongly about freedom. There’s nothing like freedom. You’re brave people. It’s a shame what’s happened to your country.”

A nationwide internet outage has gripped Iran, according to London-based internet monitoring group NetBlocks, shortly after massive crowds poured into the streets following calls for nationwide protests.
The shutdown, also confirmed by Tehran-based outlets, comes as anti-government protests continue to escalate and demonstrators take to the streets in the capital and nationwide despite deadly crackdowns by security forces.
“The incident follows a series of escalating digital censorship measures targeting protests across the country and hinders the public's right to communicate at a critical moment,” Netblocks added.
Iran has cut internet access before during mass unrest in 2022, 2019 and 2009. Those moves coincided with deadly attacks on demonstrators which ultimate quashed the protest movements.
Social media platforms are routinely difficult for Iranians to access even in normal times, with official curbs sending many users to virtual private networks, or VPNs, to bypass official censorship.
The "digital blackout", as described by Netblocks, started immediately after huge crowds of people took to the streets across the country heeding a call for nationwide protests at 8 pm by Prince Reza Pahlavi.
Iran is in the midst of a nationwide internet blackout, with live network metrics confirming a sharp drop in connectivity, internet monitoring group NetBlocks said in a post on X.
“The incident follows a series of escalating digital censorship measures targeting protests across the country and hinders the public's right to communicate at a critical moment,” Netblocks added.