It comes after Israel carried out a wave of fresh strikes on southern Lebanon on Saturday morning.
The Iranian military said it had reclosed the Strait of Hormuz on Saturday after continued Israeli strikes on southern Lebanon, according to the Fars state news agency.
The military said the decision had been made “in view of the flagrant bad faith and breach of covenant by America regarding the failure to implement the first clause of the end-of-war agreement, and in reaction to the relentless and continuous violation of the ceasefire by the Zionist regime in southern Lebanon”.
It warned that subsequent steps would also be taken if aggression continued.
The Strait of Hormuz is one of the world’s most crucial oil and gas transit chokepoints. Iran had closed the Strait earlier this year in response to US and Israeli strikes on its territory, throwing global energy markets into chaos.
Reopening the waterway had been a key part of the recently signed memorandum of understanding between Washington and Tehran, which aims at bringing the war to an end.
Referencing the agreement after the closure was announced on Saturday, a spokesperson for the Iranian foreign ministry told Fars: “The other side must take the necessary measures as soon as possible, otherwise the entire agreement will be in jeopardy”.
US and Iranian officials were due to meet in Switzerland along with mediators from Qatar and Pakistan on Friday to begin negotiations on the implementation of the agreement.
That meeting was postponed, but US media has reported that US special envoy Steve Witkoff has since arrived in Switzerland. The Iranian foreign ministry confirmed to Fars that a delegation would attend the meeting, where it would “demand the implementation of the other side’s commitments”.
It comes after Israel carried out a fresh wave of strikes on southern Lebanon on Saturday morning following the announcement of a ceasefire between Israel and the Iran-backed militant group Hezbollah on Friday.
At least 16 people were killed and 12 were injured in the strikes on the Nabatieh area, Lebanon’s civil defence agency said.
The Israel Defense Forces said the strikes were in response to its forces coming under fire from more than 50 Hezbollah launches in southern Lebanon overnight.
“Among the targets struck were rocket launch positions, weapons storage facilities, and command centers,” it said of its strikes on Lebanon.