FORT MEADE, Md - Court-martial prosecutors wrapped up their case on Tuesday against the soldier charged with providing a trove of secret material to WikiLeaks in the biggest leak of classified files in US history.

Private First Class Bradley Manning, 25, faces 21 charges, including espionage, computer fraud and, most seriously, aiding the enemy. Manning could face life in prison without parole if convicted.

Judge Colonel Denise Lind allowed the final prosecution witness, Daniel Lewis, a counterintelligence adviser at the Defense Intelligence Agency, to testify in a closed session. An unclassified summary of his testimony - largely about the value of the material Manning provided to WikiLeaks - will be read into the record.

Lewis was the government's 28th in-person witness since the trial started on June 3. More than 50 written statements from witnesses have also been submitted by prosecutors.

Lind set a court recess from Wednesday to Monday, when "we will proceed with the defense case," she said.

The defense has listed 46 potential witnesses and the trial is scheduled to run to August 23.

Lawyers for Manning have described him as naive but well-intentioned in wanting to show the American public the reality of war in Afghanistan and Iraq.

Army prosecutors contend US security was damaged when the WikiLeaks anti-secrecy website published classified information supplied by Manning. They say Manning obtained more than 700,000 classified files, combat videos and diplomatic cables while he was a junior intelligence analyst in Iraq in 2009 and 2010.

Among the accusations of harm to the United States, the former head of the Guantanamo Bay prison in Cuba has testified that the leaking of details of prisoners held there threatened "serious" damage to national security.