The authorization allows for the delivery and sale of Iranian crude oil and other petroleum products loaded onto ships before March 20, and will last through April 19, the Treasury said in a statement.

The move by the Office of Foreign Assets Control, which Treasury Secretary Scott Bessent had said Thursday was under consideration, follows a similar lifting of sanctions on Russian oil at sea.

Iran's de facto blockade of the Strait of Hormuz, through which 20 percent of the world's oil and gas normally flows, and the numerous attacks on energy infrastructure in the Middle East, have sent crude oil prices soaring.

Bessent described the move in a statement Friday as a narrowly tailored, short-term authorization that follows President Donald Trump's intention to "maximize the flow of energy to the world" and ensure market stability.

"At present, sanctioned Iranian oil is being hoarded by China on the cheap," Bessent said in a statement.

"By temporarily unlocking this existing supply for the world, the United States will quickly bring approximately 140 million barrels of oil to global markets, expanding the amount of worldwide energy and helping to relieve the temporary pressures on supply caused by Iran."

Tehran, however, said Friday it had no surplus crude oil to offer to international markets.

"Currently, Iran basically has no surplus crude oil left on the water or for supply in other international markets, and the US treasury secretary's statement is solely aimed at giving hope to buyers," Iranian oil ministry spokesman Saman Ghoddoosi wrote on X.

The Treasury's authorization on Friday does not apply to deliveries of oil to Cuba, North Korea or Russian-occupied areas of Ukraine.

Oil markets ended higher Friday, although they remained below the $120-per-barrel threshold which has been approached multiple times since the conflict began three weeks ago.

A barrel of North Sea Brent crude gained 3.26 percent to $112.19. Its US counterpart, the traditionally cheaper West Texas Intermediate (WTI), rose 2.27 percent to $98.32.