Lawyers for the United States launched a fresh attempt on Wednesday to have Julian Assange extradited from Britain, arguing that concerns about the WikiLeaks founder's mental health should not prevent him from facing justice in the U.S.

The 50-year-old Australian is wanted in the United States on 18 criminal charges, including breaking a spying law, after WikiLeaks published thousands of secret U.S. files and diplomatic cables in 2010.

Lawyers acting for the United States are appealing against a Jan. 4 ruling by a London District Judge that Assange should not be extradited because his mental health problems meant he would likely commit suicide in a U.S. prison.