UK natural gas prices rose above 154 pence a therm on Monday, marking a fresh three-week high as disruption to Gulf LNG (liquefied natural gas) supplies continued and U.S.-Iran negotiations stalled. The market was also weighed by renewed Israeli strikes against Tehran-backed Hezbollah in Lebanon and new U.S. threats of additional sanctions on Iran, developments that further clouded the chances of an imminent agreement to reopen the Strait of Hormuz (key Gulf shipping route). Traffic through the waterway has dropped sharply after recent attacks on vessels, underscoring persistent security risks for energy flows. In Europe, the supply picture is being complicated by gas inventories that remain below historical averages and are still behind the pace needed to comfortably reach pre-winter storage targets. Heatwaves across Southern and Central Europe have added to the pressure by lifting demand for gas-fired power generation, diverting more supply away from storage rebuilding.