WASHINGTON (Reuters): Elon Musk said he refused a Ukrainian request to activate his Starlink satellite network in Crimea’s port city of Sevastopol last year to aid an attack on Russia’s fleet there, saying he feared complicity in a “major” act of war.

The billionaire businessman made the comment on his social media platform X after CNN cited an excerpt from a new biography of Musk that says he ordered the Starlink network turned off near the Crimean coast last year to disrupt the Ukrainian sneak attack.

In the post on X – formerly known as Twitter – late on Thursday, Musk said he had no choice but to reject an emergency request from Ukraine “to activate Starlink all the way to Sevastopol”. He did not give the date of the request and the excerpt did not specify it.

“The obvious intent being to sink most of the Russian fleet at anchor,” Musk wrote. “If I had agreed to their request, then SpaceX would be explicitly complicit in a major act of war and conflict escalation.”

Russia, which seized the strategic Crimea peninsula in 2014, bases its Black Sea Fleet in Sevastopol and has used the fleet in a de factor blockade of Ukrainian ports since its full-scale invasion in 2022.

The Russian fleet fires cruise missiles at Ukrainian civilian targets, and Kyiv has launched attacks on Russian ships using maritime drones.

According to CNN, Walter Isaacson’s new biography Elon Musk, to be released by Simon & Schuster on Tuesday, says that when Ukrainian explosive-laden submarine drones last year approached the Russian fleet, they “lost connectivity and washed ashore harmlessly”.

It said Musk’s decision, which left Ukrainian officials begging him to turn the satellites back on, was driven by an acute fear that Russia would respond to a Ukrainian attack with nuclear weapons.

CNN said that according to the biography, this was based on Musk’s conversations with senior Russian officials and his fears of a “mini-Pearl Harbor”.

In August, a Russian warship was seriously damaged in a Ukrainian naval drone attack on Russia’s Black Sea navy base at Novorossiysk, the first time the Ukrainian navy has projected its power so far from the country’s shores.

SpaceX, through private donations and under a separate contract with a U.S. foreign aid agency, has been providing Ukrainians and the country’s military with Starlink internet service, a fast-growing network of more than 4,000 satellites in low Earth orbit, since the beginning of the war in 2022.

The Pentagon said in June that SpaceX’s Starlink had a Department of Defense contract to buy satellite services for Ukraine.

A Pentagon spokesperson declined to comment on Musk’s decision but said: “The department continues to work closely with commercial industry to ensure we have the right capabilities the Ukrainians need to defend themselves.”