The Trump administration will temporarily lift summer gasoline regulations as prices at the pump near $4 a gallon amid the Iran war. 

The emergency fuel waiver allows refiners and retailers to sell E15 gasoline, which is blended with 15% ethanol, over the summer, the U.S. Environmental Protection Agency (EPA) announced Wednesday. 

Restrictions on selling E10 gasoline, which contains 10% ethanol, will also be temporarily lifted, according to the agency. Normally, federal rules require a switch to more costly summer blends from June 1 through Sept. 15 because gas with higher ethanol content can evaporate more easily in hot weather, contributing to air pollution. 

The waivers take effect on May 1 and will be in place through May 20. 

“EPA is working with our federal partners to reduce unnecessary costs and uncertainty and ensure that gas prices remain affordable for all Americans through the summer,” EPA Administrator Lee Zeldin said in a statement. “This emergency action will provide American families with relief by increasing fuel supply and consumer choice.”

The waiver marks the White House’s latest effort to curb rising gas prices stemming from the war in Iran, which has effectively closed the critical Strait of Hormuz and cut off global oil supplies, driving up energy prices. 

The Trump administration has taken other steps to try to tame prices by boosting supply, including ordering the release of 173 million barrels of oil from the Strategic Petroleum Reserve, waiving the Jones Act to allow foreign ships to move fuel between U.S. ports, lifting Russian oil sanctions and other measures.

Last week, the International Energy Agency, an intergovernmental organization, called on governments, businesses and consumers to reduce their energy consumption by driving less and taking other steps to ease demand. 

The EPA said it will monitor fuel supplies and is prepared to extend the emergency fuel waivers “as long as the fuel supply circumstances warrant such action.”