More than 8 million barrels of oil transited the Strait of Hormuz on Sunday with U.S. military assistance amid the renewed fighting with Iran, the U.S. Energy Department told CNBC in a statement. "The U.S. military will ensure oil flows continue, with or without the Iranians, to keep markets well supplied," an Energy Department spokesperson said Monday.
Total flows out of the Middle East Gulf region are averaging 15 million barrels per day, the spokesperson said. Ship tracking firms recorded a steep drop in traffic through Hormuz over the last week, after Iranian attacks on commercial vessels sparked renewed fighting between Washington and Tehran.
Fourteen ships transited Hormuz on Sunday, four of which were crude oil tankers, a decline of about 60% compared with the 37 vessels that crossed the same day last week, according to data from the trade intelligence firm Kpler. More than 100 ships transited Hormuz daily before the U.S. and Israel launched the war with Iran on Feb. 28.
About 20 million barrels per day of oil products were exported through Hormuz pre-war. President Donald Trump said Monday that he would reimpose the U.S. naval blockade against Iran, but for Iranian ships only. Trump also demanded that other ships crossing through pay the U.S. 20% of the value of their cargo as reimbursement for protection. U.S.
Central Command said over the weekend that Hormuz remains open and traffic is flowing through the strait. Some ships transit the southern route with their transponders turned off, making it difficult to know for certain how many vessels are using the corridor. The security situation in Hormuz rapidly deteriorated over the past week.
Iran has repeatedly attacked commercial ships transiting a U.S.-protected sea lane that hugs the coast of Oman. Tehran is demanding that all ships use a northern route through its territorial waters. has launched repeated rounds of strikes on Iran in retaliation for the ship attacks. Tehran struck back by firing on U.S. allies in the Gulf.
Ships are increasingly using the Iranian route after the vessel attacks, according to Kpler. Traffic through the southern corridor protected by the U.S. military had "effectively collapsed" on Saturday, analysts at the maritime intelligence firm Windward said in a social media post. Kpler also noted that traffic through the Omani route had all but disappeared over the weekend.
More than 9.2 million barrels of Iranian crude have passed through Hormuz since Trump declared the ceasefire with Tehran over on July 8, said Matt Smith, director of commodity research at Kpler. — CNBC's Pippa Stevens contributed to this report