Polish Prime Minister Donald Tusk has called for a unified European response to Russian aggression, including the establishment of a naval policing mission to secure the Baltic Sea. 

Speaking at a summit of Nordic and Baltic leaders in Harpsund, Sweden, on November 27, Tusk said Europe needed collective strength and cooperation to counteract threats from Moscow.

The proposal for a Baltic Sea policing initiative comes amid growing concerns over maritime security following incidents such as the recent severing of undersea communication cables linking Finland to Germany and Sweden to Lithuania. 

A Chinese-flagged bulk carrier, Yi Peng 3,  which had sailed from Russia, is suspected of causing the damage. It passed close to the two cables and its anchor appears to have been damaged, raising suspicions that it had dragged its anchor along the seabed, in a similar fashion to the Chinese vessel Newnew Polar bear last year, which damaged a gas pipeline between Finland and Estonia.  

Swedish Prime Minister Ulf Kristersson urged China to order the Yi Peng 3 to move to Swedish waters to help the investigation. The Financial Times reported him as saying: “We are extremely careful not to rush to conclusions, not to accuse anybody of anything that is not well grounded. On the other hand, we take it very, very seriously. We do not simply assume it was just an accident . . . This is not the first time.”

Russia said suggestions of its involvement in the incidents were “ridiculous”. This is the second time in little more than a year that a Chinese vessel has been suspected of deliberately sabotaging undersea cables.

“There is no direct connection between the policing initiative and recent events at sea, but I believe it will be better for all of us if we maintain full control over our territorial waters,” Tusk said in Stockholm, flanked by peers from Sweden, Finland, Norway, Denmark, Iceland, Lithuania, Latvia, and Estonia.

The Baltic Sea is bordered by nine Nato nations and Russia, which stations two naval fleets in the region, in St. Petersburg and Kaliningrad.

Poland is looking more and more north to its Nordic and Baltic Nato allies, following the populist shift in Central Europe towards Moscow. The Nordic and Baltic states share Poland's hawkish stance towards Russian dictator Vladimir Putin, and are also ramping up their military spending and co-operating more intensively to defend the Baltic Sea theatre against Russian threats. 

The Baltic Sea initiative aligns with warnings about Moscow’s regional ambitions. Sweden’s former defence chief, Micael Byden, cautioned earlier this year that the Kremlin sought control over the strategically vital sea, which he said "must not become Putin's playground where he terrifies Nato members".

The meeting in Stockholm also focused on providing continued support for Ukraine as it resists Russia’s full-scale invasion.

“In the coming months, we will step up our support [for Ukraine], including to the Ukrainian defence industry, and we will invest in making more ammunition available to Ukraine,” a statement from the summit participants said.

“Ukraine’s courage and resilience will be backed by strong and steadfast support by our countries whereby military assistance is an integral part. We encourage others to do the same,” the statement also said. 

“It is the Ukrainians, standing up to Russia, who ensure the rest of us remain safe. If Ukraine loses, we all lose,” Tusk said, cautioning against any agreements on a ceasefire that could destabilise the region, were they signed on Russia’s conditions. Incoming US President Donald Trump has boasted that he could end the Ukraine war in "24 hours".