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 French soldier was killed and three others wounded in an ambush Saturday on U.N. peacekeepers in Lebanon that French President Emmanuel Macron blamed on Hezbollah, an accusation the group has denied.

The attack follows an agreement between Israel and Lebanon on Thursday for a 10-day ceasefire to negotiate an end to six weeks of fighting between Israel and the Iran-backed group.

The Israeli military said Saturday it had established a "Yellow Line" demarcation in southern Lebanon, similar to the one separating its forces from territory still held by Hamas in Gaza, adding that it had already struck suspected militants approaching its troops along the line.

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.

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.

President Joseph Aoun said on Friday that Lebanon is on the verge of a "new phase" of "permanent agreements," after the ceasefire in the Israel-Hezbollah war went into force.

"Now, we all stand before a new phase," Aoun said in his first speech to the nation since the truce, adding that "it is the phase of transition from working on a ceasefire to working on permanent agreements that preserve the rights of our people, the unity of our land, and the sovereignty of our nation."

Lebanese state media said an Israeli strike on a motorcycle in the south killed one person on Friday, despite the start of a 10-day ceasefire in the Israel-Hezbollah war.