Staff writersUpdated June 22, 2026 — 10:22am,first published June 22, 2026 — 5:30amMarket jitters returned to the Australian sharemarket with the start of the new trading week, with investors treading cautiously as talks between Washington and Tehran were clouded by a renewed threat from US President Donald Trump to strike Iran, sending oil prices up again.The S&P/ASX 200 slipped 16.20 points, or 0.2 per cent, to 8812.50 as of 10.15am AEST, following its modest 0.3 per cent gain last week when the peace deal was announced. The Australian dollar edged down 0.1 per cent to US70.02¢.“A potential unravelling of the US-Iran Memorandum of Understanding, which remains incredibly fragile given the events over the weekend,” is one of the biggest risks to sharemarkets, Tony Sycamore, an analyst at IG in Sydney, wrote in a note to clients.The Middle East war continues to shape markets.Louie DouvisAs the meetings between the two countries got underway on Sunday in Switzerland, Trump said in a social media post that he would strike Iran again if it doesn’t “immediately stop their highly paid PROXIES in Lebanon from causing trouble.”It comes after Tehran claimed on the eve of the talks that it closed the Strait of Hormuz again over Israel’s ongoing military campaign in Lebanon against the Iranian-backed Hezbollah militant group. The immediate impact on Hormuz traffic was unclear, but even before the recent ceasefire, millions of barrels of oil had been quietly escaping the waterway each day.Speaking on Sunday to Fox News, Trump said he told Iranian leaders directly that if they close the strait again, “you won’t even make it back” to Iran, using an expletive. Trump has threatened to impose American tolls in the strait if a final deal with Iran isn’t reached in 60 days.Oil prices rose after resuming trade on Monday morning, with Brent, the international standard, advancing 1.3 per cent to $US81.65 per barrel, while US oil added 2.5 per cent to $US77.75.While a hard-won interim deal has signalled a pause in US-Iran hostilities, Sunday’s discussions are likely just the start of protracted wrangling that will span topics including Iran’s nuclear capabilities and economic relief for Tehran.With US cash markets closed for the Juneteenth holiday, S&P 500 futures declined 0.6 per cent this morning, pointing to losses when Wall Street starts its week.The US benchmark posted its best week last week since the end of May. The latest developments are a test to the optimism that has seen a technology-led rally in stocks gain further momentum after the US and Iran lifted their months-long dual blockade of the Strait of Hormuz late last week.“Of course, with Trump there can always be some derailment along the way, but we believe that we’re set into a new phase of de-escalation,” said Alexandre Drabowicz at Indosuez Wealth Management. He advised investors not to rush to conclusions about a permanent deal.UK gilts led a broad advance in European bond yields after Greater Manchester Mayor Andy Burnham won a seat in Parliament, handing him a pathway to challenge Prime Minister Keir Starmer for his job. Investors are debating whether a Burnham premiership might shift to a looser fiscal policy.The pound slid toward a fresh low for the year as Starmer is expected to set out a timetable for his departure as PM in the coming days, and may concede power as soon as Monday, people familiar with the matter said.Trump said in a post on Truth Social on Sunday that Starmer was to resign. A UK official said nothing had been communicated to Trump from the government, and he had not spoken to Starmer.With Bloomberg, APThe Market Recap newsletter is a wrap of the day’s trading. Get it each weekday afternoon.From our partners