WASHINGTON, Nov. 17 (Xinhua) -- The U.S. Department of Defense is prepared to launch a broad investigation to review how military troops deal with potential problems among themselves, said the Pentagon on Tuesday.

    Pentagon spokesman Geoff Morrell told reporters that the review, which is still in the planning stages, would cover all corners of the defense department.

    The measure is taken in light of a massacre in an Army base in Texas, Fort Hood, where a 39-year-old military psychiatrist, Maj. Nidal Hasan, killed 13 and wounded about 30 others.

    U.S. media reports said that Hasan was under watch before the killings but the investigation was ceased for some unknown reason.

    New evidence was found that Hasan had been in contact with someone on a U.S. "kill or capture" list of al-Qaida and Taliban targets.

    Morrell said that Hasan's case raised issues even larger than the Army, so Defense Secretary Robert Gates wants to take a unified look at procedures.

    Apart from that, the Army is also ready to start a separate investigation into the case, said the military.

    President Barack Obama called last week for a thorough investigation of the mass shooting at Fort Hood on Nov. 5.

    "Given the potential warning signs that may have been known prior to these shootings, we must uncover what steps -- if any -- could have been taken to avert this tragedy," he said.

    Members of Congress have also called for investigations into whether government intelligence agencies failed to recognize clues that Hasan "had fallen under the thrall of extremist ideology."