Russian President Vladimir Putin has issued a warning that Moscow may seize British vessels in response to recent European sanctions targeting Russia’s so-called shadow fleet, a collection of tankers used to transport oil and generate revenue amid the ongoing conflict in Ukraine. This announcement came during a naval exercise in the Pacific, where Putin condemned recent British and European Union actions as unlawful interference with Russian commercial shipping.

The UK and EU have intensified sanctions against Moscow by authorizing the seizure of Russian vessels suspected of illicit activity related to oil exports. These measures, enacted last month, also permit EU member states to sell any oil or cargo recovered from the detained ships. Putin described these seizures as acts of “piracy and robbery” and suggested that Russia would retaliate “wherever we ourselves deem it necessary and appropriate” if such tactics persist.

Viktor Liina, commander of Russia’s Pacific Fleet, added that Britain and France—both countries involved in recent seizures—could become targets of Russian countermeasures. He stated that Russian forces are closely monitoring maritime traffic in the Asia-Pacific region and gathering intelligence on commercial ships, including those belonging to so-called “unfriendly states.” According to Liina, more than 1,000 vessels have passed through waters claimed by Russia near Japan, of which 379 hail from hostile countries, including 26 from the UK and nine from France.

International law experts and former officials observe the potential risks of escalating naval confrontations. John Foreman, a former British defense attaché in Moscow and Kyiv, noted that the possibility of Russia matching British interdictions has existed since the shadow fleet boardings began. He indicated that the UK Ministry of Defence and Navy have precautionary measures in place in coordination with commercial shipowners. Foreman said it was unclear what legal grounds Putin might invoke for retaliatory actions, but cautioned that Russia has previously disregarded international norms. The UK’s enforcement relies on Article 110 of the United Nations Convention on the Law of the Sea, which allows warships to detain vessels suspected of flying false flags.

A UK government spokesperson reaffirmed the legality and necessity of British operations against the shadow fleet, condemning Russia’s activities as fueling the war effort in Ukraine. The spokesperson emphasized that the seizure of the Russian tanker Symphony in June complied with international law, and defended UK and commercial vessels as operating within established maritime regulations, in stark contrast to Russian actions.

Analysts suggest that Putin’s recent rhetoric may also be aimed at consolidating domestic support ahead of impending Russian elections, projecting an image of toughness amid geopolitical tensions.