"Last night, coinciding with the downing of US drones, the 'Strategic Action for the Security and Sustainable Progress of the Strait of Hormuz and the Persian Gulf' bill was formally introduced in Iran's Parliament," Ebrahim Azizi wrote on X.
"We remain steadfast in defending our red lines, particularly regarding the management of the Strait of Hormuz," he added. "This is the first step; subsequent measures are forthcoming."
US-Iran fighting reignited last week over disagreements on how the vital strait would be managed, throwing into question a framework deal signed last month seeking to end the Middle East war.
Tehran envisages itself as overseeing the strait and wishes to impose fees on transiting vessels -- a demand Washington has strongly rejected.
More from WorldPresident Donald Trump on Monday said the United States was "taking over" Hormuz and reimposing a blockade of Iranian ports, floating a 20 percent fee on cargo transiting the waterway.
Iran had on Sunday declared that the strait was closed, after having opened it to shipping during negotiations with the United States seeking a final deal to permanently end the war.
Iran's legislature had been suspended after the war broke out in late February, but resumed sessions on Monday.
Parliament is headed by Mohammad Bagher Ghalibaf, who also acts as chief negotiator in talks with Washington, a role that has thrust him further into the political limelight in recent months.
A number of lawmakers are opposed to any negotiations with the United States, and expressed concern over having no say on the signing of the memorandum of understanding with Washington.
