Tehran has formally notified the International Maritime Organization (IMO) that “non-hostile vessels” may now navigate the Strait of Hormuz, provided they act “in co-ordination with Iranian authorities”.

According to a letter circulated among IMO member states on March 24 and seen by the Financial Times, Iran’s foreign ministry said Tehran had taken “necessary and proportionate measures to prevent the aggressors and their supporters from exploiting the Strait of Hormuz to advance hostile operations against Iran”.

The Financial Times cited Tehran's clarification that commercial tonnage linked to the US, Israel, and “other participants in the aggression, do not qualify for innocent or non-hostile passage”.

The critical 21-nautical-mile (38.9 km) maritime chokepoint has been virtually impassable since the US-Israel conflict erupted on February 28. Around 3,200 commercial ships remain trapped in the Gulf. Operators are unwilling to risk the transit, leaving crews increasingly depleted of essential provisions. At least 22 vessels have sustained direct hits. Consequently, the IMO – the UN agency responsible for international shipping standards – recently convened an emergency summit to negotiate a humanitarian corridor for stranded seafarers.

Recent vessel-tracking data indicates Iranian authorities are routing a fraction of maritime traffic through their territorial waters to facilitate identity verification. Furthermore, the Financial Times reported that certain operators have paid fees reaching $2mn to Iran to secure safe transit through the Gulf, citing intelligence from Lloyd’s List sources.

The operational toll on the maritime sector is mounting. SV Anchan, CEO of the US-based Safesea Group, told the Financial Times that “all the governments should come forward and try to help solve this situation.” He confirmed the company’s vessel, the Safesea Vishnu, was struck on March 11 and is now “beyond repairable”.

Despite diplomatic pressure and threats from US President Donald Trump, Tehran shows no indication of relinquishing its strategic leverage over the waterway. Iranian politicians suggest the pre-war status quo has irrevocably ended. Lawmakers are currently drafting legislation to permanently regulate traffic.

MP Mansour Alimardani told Iran’s Mehr News Agency that while Tehran historically pursued international co-operation, “mounting pressure from illegal sanctions has led the Islamic republic to temporarily restrict cargo passage in order to demonstrate its capability in managing global energy transit.”

Alimardani outlined that the proposed parliamentary framework serves a dual mandate: to reciprocate against nations that supported US sanctions, and to force a transition away from the US dollar in regional energy transactions. The draft requires legal review before a parliamentary vote.