European natural gas futures were up on Thursday, reversing losses from earlier in the day, after Iran's Supreme Leader, Ayatollah Mojtaba Khamenei, issued a directive forbidding near-weapons-grade uranium from being sent abroad.
The front-month Dutch TTF gas contract rose 0.51% to 49.680 euros ($57.61) per megawatt hour, while the UK front-month NBP contract was up 0.49% to 121.300 British pence ($1.63) per therm.
Hardening its stance on one of the key US demands for any peace deal, Tehran has reportedly said that its enriched uranium will stay within its borders, according to a Reuters report, citing two senior Iranian sources.
Separately, Reuters reported that senior Israeli officials said US President Donald Trump gave Israel assurances that any peace deal with Iran was subject to its weapons-grade uranium being taken out of the country.
This has diminished market optimism about a quick end to hostilities in the Middle East, which is now nearing the three-month mark.
The strategically crucial Strait of Hormuz, which accounted for one-fifth of global LNG flows, remained effectively closed for the 12th week running, with just two vessels transiting over the past 24 hours, according to the Hormuz Strait Monitor.
European markets remained under pressure, with Norway, the region's biggest piped gas supplier, expecting "capacity cuts deeper than previously expected over the next week," as more seasonal work is expected at the Troll gas field, Daniel Hynes, a senior commodity strategist at ANZ, said.
Europe is also grappling with depleted gas inventories, which are currently at 36.87% of capacity, compared to 44.93% a year ago, data from Gas Infrastructure Europe said.
Inventories were also significantly below the five-year average for this period, at 50.6% of capacity, according to the Swiss Federal Office of Energy.
These factors coincide with a late-May heatwave forecast across the continent, with much of Europe expected to experience a 'heat dome' phenomenon.
Countries including Spain and Portugal are projected to see temperatures climb to the mid-to-upper 30s Celsius, likely boosting cooling-related gas demand, according to Severe Weather Europe.