Gen. Paul Nakasone, the head of US Cyber Command, told Sky News on Wednesday that the US has been conducting “offensive” cyber operations to support Ukraine in its war against Russia.

Nakasone said the US has “conducted a series of operations across the full spectrum; offensive, defensive, information operations.” He didn’t share any details of the cyber operations, but his disclosure is the first time a US official has admitted to launching cyberattacks to support Ukraine in the war.

NATO has stepped up cyber cooperation with Ukraine in recent months by allowing Kiev to join its cyber defense center, known as the Cooperative Cyber Defence Centre of Excellence (CCDCOE). On Monday, Ukrainian officials met with the CCDCOE steering committee for the first time.

Nakasone’s disclosure is the latest example of US support for Ukraine that risks provoking Moscow. After Russia invaded, President Biden warned that a Russian cyberattack was “coming,” but it never materialized.

In recent years, US and NATO officials have signaled they believe cyberattacks could potentially start a war. A few days after Russia invaded Ukraine, a NATO official told Reuters that a cyberattack on an alliance member could trigger Article 5 collective defense clause, which states an attack on one member is an attack on all.

Last year, President Biden said that he believes the US could end up in a “real shooting war” with another power over a cyberattack. “If we end up in a war, a real shooting war with a major power, it’s going to be as a consequence of a cyber breach of great consequence,” he said.

This article was originally featured at Antiwar.com and is republished with permission.