Iran and the US have continued to insist on fundamentally diverging versions of any final deal to end the ongoing war, as both sides reportedly exchanged strikes in the Persian Gulf for the second time in three days and Washington sanctioned Tehran's new Hormuz transit authority.

The US Treasury Department's Office of Foreign Assets Control placed the Persian Gulf Strait Authority on its sanctions list on Wednesday, saying it was "a new attempt by the Islamic Revolutionary Guard Corps to monetise its campaign of state-sponsored terror by extorting vessels transiting the Strait of Hormuz."

Treasury said the PGSA "spearheads an Iranian-controlled scheme that flagrantly violates international law and US sanctions," and warned that any payment to the body for passage through the strait could expose individuals and companies to sanctions.

Iranian officials had previously spoken publicly about a fee of $2 million (€1.7m) per vessel.

The Washington-based Institute for the Study of War think tank (ISW) said senior Iranian officials were framing control over the strait as a strategic necessity and a core element of deterrence against the US and Israel.