The U.S. military said it has brought 22 new charges against a soldier accused of leaking hundreds of thousands of sensitive U.S. government documents that were later published by the website WikiLeaks.

Bradley Manning, a former intelligence analyst suspected of obtaining the documents while serving in Iraq, is being held at a Marine base in Virginia as U.S. officials investigate last year's publication of State Department cables and military documents related to the wars in Iraq and Afghanistan.

The U.S. Army's new charges against Manning, the result of a seven-month probe, include 'aiding the enemy' and 'wrongfully causing intelligence to be published on the Internet,' the military said in a statement.

Manning, 23, had previously faced a host of charges including downloading and transmitting to an unauthorized person a classified video of a 2007 helicopter attack that killed a dozen people in Baghdad, including two Reuters employees.

The WikiLeaks affair was a major blow to the United States as allies and adversaries around the world saw themselves mocked or second-guessed in secret diplomatic cables.

It also raised questions about the Obama administration's ability to keep a lock on electronic information.

The military will not seek the death penalty against Manning, it said in its statement, even though an 'aiding the enemy' charge is a capital offense under military law. But Manning could face life in prison if convicted.

The private's trial has been delayed as a panel looks into his mental state. Depending on the results of that panel, a grand jury may be convened.

Julian Assange, the Australian computer expert behind the WikiLeaks website that has been strongly condemned by the Obama administration, has denied knowing Manning. But he has accused the United States of using the jailed soldier to build a case against him.

(Reporting by Missy Ryan; Editing by Eric Walsh)