WASHINGTON (AP) — President Donald Trump on Monday extended a waiver for 90 days for foreign ships to transport goods, including oil, fertilizers and other fossil fuel products, among U.S. ports.

The president first waived the Jones Act on March 17 so that it would be easier to transport oil and refined fuels among ports, reducing price pressures after the start of the war with Iran.

The latest extension will take effect on August 17 and suggests that the U.S. might be preparing for continued price pressures as the Strait of Hormuz, a primary waterway for shipping oil and natural gas, remains effectively closed because of the war.

Unlike previous extensions, the Pentagon will consult with the Maritime Administration to decide which voyages are exempt from the 1920 law containing the Jones Act. The new waiver will only apply to cargo that are sources of energy and commodities related to agriculture such as fertilizers and soybean oil.

Taylor Rogers, a White House spokeswoman, said the administration extended the waiver “to ensure our military and key industries maintain uninterrupted access to critical resources.” Rogers added that the waiver has increased domestic deliveries of gasoline, diesel and jet fuel.