President Donald Trump issued an extension of a Jones Act waiver, allowing refiners more time to use foreign-flagged ships to transport fuel between U.S. ports to ease rising oil prices driven by the war in Iran.

White House officials said Friday that the president will extend the Jones Act waiver for 90 days. On March 18, he issued a 60-day waiver of the law, which requires goods shipped between U.S. ports to be carried only by American-built ships. The waiver is aimed at lowering the cost of transporting oil from Gulf refineries to the East Coast and other parts of the country.