A British man accused of hacking into thousands of United States government computers can be extradited to the US to face trial, a court in Britain ruled Friday.

Lauri Love, 31, faces a lengthy prison term if convicted of charges including hacking into the networks of the US Federal Reserve, US Army and NASA, among others in 2012 and 2013.

Love's supporters said he would appeal the decision.

US prosecutors argue that Love disseminated the personal information of US citizens including serving members of the military.

District judge Nina Tempia granted the US's extradition request in a hearing in London but also gave Love leave to appeal the decision to a higher court.

"I'm going to extradite Mr Love, but what I mean by that is I'm going to send his case to the Secretary of State" (for final approval of the decision), Tempia told the hearing.

Love argues he should face justice in Britain rather than the US and believes that his Asperger Syndrome condition would get worse if he was sent to an American prison.

"If you have come for justice then you have missed it," Love told journalists after the decision.

"We shouldn't look on this as even nearly the end... we will continue to fight because we're doing what's right," he added outside court.

Sarah Harrison, director of the Courage Foundation which runs a fund and campaign supporting Love, said: "This is a very disappointing ruling."

She added: "I know that Lauri's legal team will apply to appeal this ruling and the Courage Foundation will continue to support Lauri until his safety is assured."