Iran's top national security body said that the country was reviewing "new proposals" received from the United States, even as it warned that its negotiators would cut no compromises with Washington.

U.S. President Donald Trump on Saturday warned Iran not to "blackmail" Washington with its flip-flopping on the fate of the Strait of Hormuz, after Tehran declared the strategic waterway once again closed.

"We're talking to them. They wanted to close up the strait again -- you know, as they've been doing for years -- and they can't blackmail us," Trump said at a White House event.

A statement said to have been issued by Iran's supreme leader Mojtaba Khamenei warned Saturday that Tehran's navy was ready to defeat U.S. forces, as the foes sparred over the Strait of Hormuz.

Iranian gunboats fired on a tanker in the Strait of Hormuz on Saturday, a British maritime security agency reported, after Iran's military reversed a pledge to open the route to shipping.

No date has been set for the next round of Iran–U.S. peace talks brokered by Pakistan following the failure of an initial round, Iran's deputy foreign minister said on Saturday.

Iran's central military command announced on Saturday it would resume "strict management" of the Strait of Hormuz, reversing a decision to unblock the strategic channel as part of negotiations with Washington.

U.S. President Donald Trump said Friday that the United States and Iran would jointly remove uranium from Tehran's nuclear sites with excavators under any peace deal, before the material is transferred to U.S. territory.

Trump's comment came despite Iran's foreign ministry saying earlier that the Islamic Republic's stockpile of enriched uranium would not be transferred "anywhere."

Pakistan's powerful military chief and prime minister on Saturday concluded separate visits aimed at ending the Iran war, with Field Marshal Asim Munir leaving Tehran and premier Shehbaz Sharif headed home from Turkey.

U.S. President Donald Trump told AFP on Friday there were "no sticking points" left for a peace deal with Iran, adding that an agreement was "very close."

U.S. President Donald Trump on Friday welcomed Iran's announcement that the crucial Strait of Hormuz will reopen to shipping, but said a U.S. blockade of Iranian ports would continue until a peace deal is signed.

"THANK YOU!" Trump wrote on his Truth Social platform, saying that Iran had announced the narrow waterway was "FULLY OPEN AND READY FOR FULL PASSAGE."