The United States said it had launched fresh strikes against Iran on Wednesday evening as President Donald Trump warned Tehran it "better behave".
The US military said "Iranian military capabilities used to threaten vessels" moving through the Strait of Hormuz had been targeted, and that it had separately fired on a ship attempting to violate its renewed blockade of Iran's ports.
It came after Iran claimed it had struck US military targets in the region, including in Bahrain and Kuwait, as a fifth day of renewed hostilities strained their preliminary deal to end the war.
Iran's top negotiator, Mohammad Bagher Ghalibaf, meanwhile told state media Tehran had "no reason" to abide by the deal if it did benefit from it.
Trump had threatened late on Tuesday to attack bridges and power plants should Iran not return to talks next week.
Asked by reporters late on Wednesday whether he would give a deadline before doing so, he responded: "I don't like giving deadlines, but they pretty much know, they know the story... they better behave."
He later told delegates at a defence summit that Iran was "not happy right now".
"They want to settle so badly. They don't like what we're doing," he said. "We'll find out whether we want to settle with them or if we just finish it off."
Ghalibaf however said Iran's national security depended on Tehran maintaining "Iranian arrangements" in the strait.
He added that negotiation - along with war - was part of Iran's strategy of resistance as it engaged an "existential" conflict with the US.
The escalation in Trump's rhetoric came after he said a 20% toll he had threatened to impose in the Strait of Hormuz would be replaced by "massive" trade and investment deals with Gulf states.
A previous threat by Trump to bomb Iran's civilian infrastructure, which was made in April, drew condemnation at the time from UN human rights chief Volker Türk, who said: "Under international law, deliberately attacking civilians and civilian infrastructure is a war crime."
The latest US strikes marked the second wave its military said it had carried out during daylight hours on Wednesday. It said it had "further degraded Iran's ability to attack commercial shipping in the Strait of Hormuz" earlier in the day.
A 90-minute wave was used to target Iran's coastal defences and cruise missile storage and launch sites on Greater Tunb Island, US Central Command (Centcom) added.
Centcom also said it had redirected two commercial vessels since reimposing its blockade on Iranian ports on Tuesday evening, which stops vessels from transiting to and from Iranian ports and coastal areas.
The blockade had previously been lifted as part of a deal that was struck by the two countries last month - known as a memorandum of understanding - that aimed to end the months-long conflict.
However, a dispute over the strait has become a key point of contention.
In response to the renewal of the US blockade, Iran's Revolutionary Guard Corps (IRGC) warned the US that it should "expect the closure of other oil and gas export routes that serve the interests of the United States and its allies". It did not elaborate on which routes could be affected.
Ongoing US-Iran hostilities have underscored the strategic importance of the Strait to the global economy, with a sharp rise in oil prices triggered by tanker traffic virtually stalling through the key shipping lane.
Source: BBC
--Agencies
