Shipping traffic through the Strait of Hormuz remained virtually at a standstill, with just three crossings recorded over a 12-hour period, shipping data cited by "Reuters" showed.
The oil tanker Nero, which is under British sanctions over Russian oil activities, has left the Persian Gulf and passed through the strait, according to satellite analysis by SynMax and tracking data from the Kpler platform.
Two other ships used the strategic waterway on Monday, entering the Persian Gulf separately. They are a chemical tanker and a liquefied petroleum gas (LPG) tanker. The LPG tanker Axon I is under separate US sanctions for trading with Iran.
Meanwhile, the truce between the United States and Iran appears to be in jeopardy. The US said it had seized an Iranian cargo ship that had attempted to circumvent the blockade. Tehran has vowed retaliation and has so far refused to join a new round of peace talks.
"Recent weeks have brought several attempts and announcements (to open the Strait of Hormuz) and while it is likely that some form of resolution will be reached at some point, the timing of a lasting breakthrough remains highly uncertain," shipbroker Clarksons said in a note on Monday.