President Donald Trump voiced frustration on Tuesday with allies he said had not done enough to support the U.S. war effort, bluntly urging them to “go get your own oil” as the conflict with Iran—and the closure of the Strait of Hormuz—drove average U.S. gas prices above $4 per gallon.

His remarks, posted on social media, followed a series of escalating attacks. U.S. strikes hit the central city of Isfahan, sending a massive fireball into the sky, while Tehran targeted a fully loaded Kuwaiti oil tanker in the Persian Gulf.

More than a month after the United States and Israel launched the campaign, the latest exchanges underscored the war’s growing intensity. The conflict has left over 3,000 people dead and severely disrupted global supplies of oil and natural gas, unsettling markets and driving up the cost of everyday goods.