The U.S. national average retail price of gasoline crossed $4 a gallon for the first time in more than three years on Monday, Reuters reported citing data ‌from price tracking services GasBuddy, as the U.S.-Israeli war with Iran continued to roil global energy markets.

The $4 per gallon milestone was last reached in August 2022 following Russia’s invasion of Ukraine and represents what some analysts have called a psychological barrier for consumers. Prices for many goods are climbing, including oil used to make gasoline, following Iran’s essential closure of the Strait of Hormuz, a key trade chokepoint.

U.S. national average retail gasoline prices have climbed about $1.06 a gallon, or 36%, since the U.S. and Israel attacked Iran at the end of February, according to Reuters.