Live updates: Follow the latest news on the Iran war
Iran’s parliament speaker said talks with the US on ending the war had made progress but stressed the arch-foes are some way from reaching a deal.
"We are still far from the final discussion," Mohammad Bagher Ghalibaf said in a televised address early on Sunday.
President Donald Trump said the US was having "very good conversations" but gave no other details.
Their statements come days before a fragile ceasefire in the US-Israeli war against Iran is due to expire, amid heightened tensions around the Strait of Hormuz.
Iran’s Islamic Revolutionary Guard Corps said on Saturday that it had moved to shut the waterway, following comments by Mr Trump that the US would maintain its blockade on Iranian ports.
The war started on February 28, when the US and Israel attacked Iran.
The conflict has killed thousands, spread to Israeli attacks in Lebanon and sent oil prices surging because of the closure of the strait, which before the war carried one-fifth of the world's oil shipments.
An Israeli soldier was killed and nine others wounded on Saturday in an explosion in southern Lebanon, where Israel is fighting Iran's ally Hezbollah.
The Israeli military said the roadside bomb had been planted by Hezbollah and that it struck several targets in response.
A French soldier was killed and three others wounded in an attack on a UN patrol in southern Lebanon on Saturday, with President Emmanuel Macron saying evidence pointed to Hezbollah.
The fighting has killed more than 2,000 people in Lebanon and devastated parts of the country's south.
A first round of US-Iran talks held in Islamabad, Pakistan, last weekend ended without agreement, while a follow-up meeting expected this weekend has yet to materialise.
In his address, Mr Ghalibaf, who has led Iran’s negotiating team in the talks, said the conflict reflected a recurring pattern in US and Israeli policy that must end.
"The Zionist regime [Israel] and America have constantly had a cycle of war-ceasefire-peace, and this cycle must be broken, and sustainable peace must be established with guarantees that war will not happen again," he said.
"We have reached conclusions on some issues, but not on others, and other proposals have been made; we are still far from a final discussion.
"We made progress in the Islamabad negotiations, but the gaps are wide and some fundamental points remain."
Iran shifted position on Saturday, moving again to restrict traffic through the Strait of Hormuz after briefly reopening it a day earlier under a US-brokered ceasefire.
Tehran said the move was in response to Washington’s continued blockade of its ports, which it described as a breach of the truce.
Mr Trump called the move “blackmail” but insisted talks were progressing, while warning the US could resume strikes if no long-term deal is reached before the ceasefire expires.
“We're talking to them … we're taking a tough stand,” Mr Trump said at the Oval Office. “We'll have some information by the end of the day,” he added, referring to ongoing talks with Iran.
Iranian officials, meanwhile, signalled readiness to escalate, saying their forces were prepared for further confrontation.
The renewed disruption has raised concerns over global energy supplies, with vessels reporting attacks in the area and hundreds of ships left waiting to transit the waterway.
