Commodity vessel traffic through the Strait of Hormuz dropped to its lowest daily level in more than three months on Monday, with shipping data recording just two tanker transits through the key energy chokepoint.

Both vessels were entering the Gulf from the Gulf of Oman. Shiptracker Kpler identified them as one very large gas carrier and one very large crude carrier, based on data available by 0657 GMT on Tuesday.

The two recorded crossings were substantially below the 10-day average of 14 commodity vessels and down from seven vessels of all types on Sunday. However, the figures remain subject to revision because some ships had switched off their navigation transponders while approaching or passing through the strait.

Separate provisional figures from Vortexa placed Monday's oil transits at 5 million barrels per day. On a seven-day moving-average basis, flows through Hormuz stood at approximately 6 million to 7 million barrels per day as of August 23.

The decline comes amid increased pressure over navigation through the waterway. Iran said it had blacklisted 45 tankers for breaching its passage rules and threatened action against vessels conducting ship-to-ship transfers with the listed ships.

Xavier Tang, senior market analyst at Vortexa, said it remained uncertain how Iran's Persian Gulf Strait Authority would enforce compliance against vessels it considers non-compliant. He added that an escalation of the regional conflict or attacks on ships at the chokepoint could affect Hormuz traffic.

Before the conflict, the Strait of Hormuz handled about one-fifth of global crude oil and liquefied natural gas flows, underlining its importance to international energy shipping.

The transit data also coincided with expanded US sanctions intended to increase economic pressure on Iran. US Treasury Secretary Scott Bessent announced the measures on Monday, although they stopped short of the most severe available restrictions. He warned that countries continuing to trade with Iran could risk losing access to the dollar-based financial system. Iran said it would retaliate and expressed confidence that its principal trading partners would resist the US pressure campaign.

Traffic through Bab el-Mandeb, the other major maritime chokepoint bordering the Arabian Peninsula, remained comparatively stable. Kpler recorded 30 vessel transits there on Monday, broadly matching the 10-day average and up from 28 crossings on Sunday.