German airline Lufthansa has announced it will cut 20,000 short-haul flights this summer, noting that the sharp rise in fuel prices has made many of these routes "unprofitable." Aircraft fuel prices have doubled since the start of the conflict between the U.S., Israel, and Iran, as clashes have slowed production and transportation across the Middle East. Other airlines, such as Air France–KLM and Delta Air Lines, have temporarily reduced some flights, while others have raised ticket prices to offset rising costs. Analysts warn that travelers should expect further price increases and additional flight cancellations if the conflict continues. The Gulf region is a major source of aviation fuel, covering about 50% of Europe's imports. Most of this supply passes through the Strait of Hormuz, which is currently effectively blocked by Iran in response to American and Israeli attacks. The rise in fuel prices reflects the importance of refineries in the Middle East. According to Energy Intelligence, the Al-Zour refinery in Kuwait alone supplies about 10% of Europe's aviation fuel imports. Meanwhile, the International Energy Agency warned last week that Europe could face aviation fuel shortages within weeks. However, the British government and the airlines themselves state that so far, they are not seeing concrete disruptions in supply.