Tighter security measures and mental health programs have been introduced at the Fort Hood army post in Texas, in the wake of the November shooting that left 13 dead, the post's commanding general said Friday.

Following a 40-day review, about a dozen changes have been introduced, most of which are made to enforce existing rules, Lt.Gen. Robert Cone told a press conference at Fort Hood.

According to a revamped gun policy, soldiers are now required to register any personal firearms taken onto Fort Hood, Cone said.

Meanwhile, the post is conducting more random searches at entry gates and has started a program training soldiers to spot signs of radicalization, Cone said.

The commander said Fort Hood has launched a behavioral health campaign, a two-year process aimed to address the short- and long-term needs of those affected by the shooting, including soldiers, their families, civilians and contractors.

After initial screenings, Cone said, about 30 percent of civilians and 20 percent of uniformed personnel required additional psychological counselling.

Army psychiatrist Nidal Malik Hasan was arrested and charged last month with killing 13 service members and wounding more than three dozen others at Fort Hood.

One of the shooting survivors, who suffered head trauma and appeared to have lost the use of an arm, remains in hospital, Cone said, adding that another 30 victims had been released from hospital.