A US-based pressure group tracking Iranian oil cargoes has called for a European port ban on Panamanian-flagged tankers in an ongoing row over sanctions enforcement.

United Against Nuclear Iran (UANI) said that Panama’s maritime authority (AMP) had been “inaccurate and deceptive” in response to its criticisms of the flag state’s record in tackling sanctions breaches.

The group claimed that the authority had failed to act despite being supplied with bills of lading, satellite images and other data that indicated Panamanian-flagged vessels were hauling Iranian crude in contravention of US sanctions. It says 39% of the tankers carrying Iranian oil are on Panama's registry.

The chief executive of UANI, Mark Wallace, said the EU should impose the same ban on Panamanian-flagged tankers as it had on Russian vessels following the invasion of Ukraine.

“This would help accomplish what the AMP refuses to do: choke off Russia’s most critical military partner, Iran, by breaking up its ability to smuggle oil,” he said.

The European Union, in concert with the US and UK, on Monday announced new sanctions against Iran, focused on individuals linked to a crackdown on anti-regime protests.

It followed the failure of talks last year to revive a 2015 agreement that would have allowed Iran to return to mainstream oil trading in return for tighter controls on its nuclear sector.

Panama’s authority defended its record on Thursday and said that it worked in “close collaboration” with the United States.

Financing terrorism

“To this end, we have established monitoring mechanisms to determine possible links between oil tankers and the transport of products that could be related to the financing of terrorism,” it said in a statement.

It has ejected 136 ships in the last four years because of direct links to the National Iranian Oil Company (NIOC), which is under US sanctions, according to local media reports.

UANI says that it has written nearly 50 letters to AMP related to some 140 vessels but only 18 had been deflagged.

Panama, which hosts the world’s largest registry with 16% of the global fleet, has also come under fire from Iran.

Iran’s Port and Maritime Organisation said that Panama had only made public decisions to deflag ships because of political pressure from the United States, according to Iran’s state-linked Press TV website.

The maritime agency said the move was “insignificant” but warned Panama of the implications of making such public statements, said Press TV.