Ukrainian President Volodymyr Zelensky has called on European governments to move beyond sanctions rhetoric and adopt hard-edged laws that would allow them to block Russian “shadow fleet” tankers from their waters and seize the oil they carry.

In a video address to leaders of the UK-led Joint Expeditionary Force, a defence coalition of 10 Northern European nations meeting in Helsinki, Zelensky argued that Europe must close loopholes that still enable Moscow to export energy and fund its war against Ukraine.

“We need joint action to create strong laws in Europe that allow countries to block Russian tankers and confiscate the oil,” he said, framing the measure as a strategic step to erode the Kremlin’s leverage over European energy security. “This should be a real tool to take away Russia’s ability to pressure Europe.”

Zelensky urged JEF members not only to adopt such measures nationally but to lobby within the wider European Union for a coordinated legal framework. “Please also help others in Europe move these decisions forward and implement them at home,” he said, stressing that fragmented enforcement leaves gaps that Russian traders can exploit.

The Ukrainian leader praised recent actions by Denmark, Sweden and France, which have intercepted and detained tankers suspected of belonging to the shadow fleet. He described those seizures as “a clear demonstration that enforcement is not only possible but effective,” arguing that they should serve as a model for other coastal states.

The so-called shadow fleet is a loose network of hundreds of tankers that Western officials say Russia and its partners use to circumvent price caps and sanctions imposed after the full-scale invasion of Ukraine. Many of the vessels are older, sail under flags of convenience, operate with opaque ownership structures and lack standard insurance, raising environmental and safety concerns in addition to geopolitical ones.

European authorities have intensified scrutiny of these ships. The French navy recently detained a third suspected shadow fleet tanker in the Mediterranean. In Sweden, officials seized the Sea Owl I in mid-March and arrested its captain on allegations of falsified documents and breaches of maritime rules.

Britain has also hardened its stance, announcing that its military is now authorised to board and seize sanctioned shadow fleet vessels entering UK territorial waters. Across the EU, nearly 600 ships are currently listed under sanctions regimes linked to Russia’s oil trade.