European natural gas futures extended gains in after-hours trading Thursday after US President Donald Trump threatened tougher economic sanctions on Iran, as tensions between Washington and Tehran intensified.
Front-month Dutch TTF futures rose 3.351% to 65.505 euros ($76.45) per megawatt-hour, while UK NBP futures gained 3.626% to 162.060 British pence ($2.21) per therm.
European gas prices earlier climbed above 65 euros/MWh, reaching their highest level since January 2023, Trading Economics reported. Prices have risen more than 130% since the start of the year, according to Euronews.
Trump on Wednesday threatened "tremendous" punishment for countries that help or do business with Iran, increasing pressure on Tehran to reopen the strategic waterway. The warning on Truth Social followed Trump's earlier statement that there were no negotiations with Tehran and none were planned, while a naval blockade remained in place.
The months-long disruption to traffic through the Strait of Hormuz has halted LNG deliveries from Qatar, forcing European utilities to compete with buyers in Asia and other markets for available cargoes and raising concerns over supplies ahead of winter.
Reduced LNG inflows, coupled with increased cooling demand during a heatwave, have slowed gas storage injections across Europe. That has raised the risk that inventories could enter the winter below more comfortable levels, adding to upward pressure on prices.
EU gas storage facilities were 61.61% full, compared with 74.24% at the same point last year, according to Gas Infrastructure Europe. Inventories were also below the five-year average of 78.7% for the period, according to the Swiss Federal Office of Energy.