A US military judge has ruled that the soldier accused of the 2009 shooting rampage at Fort Hood can continue to represent himself, refusing a request from his lawyers to take over the case despite concerns the accused was intent on securing a death sentence.

The trial of Major Nidal Hasan, who has admitted shooting dead 13 people at the Texas military post four years ago, reopened on Thursday after being halted a day earlier to consider the request by his court-appointed standby defence team.

They argued it was against their "professional obligations" to aid Hasan's apparent attempt to convince jurors of his guilt, and be sentenced to death.

However, the judge sided with Hasan on Thursday, saying it was clear the lawyers simply disagreed with Hasan's defence strategy. The judge then ordered the lawyers to continue aiding Hasan after they asked to be removed from the trial.

Hasan does not argue that he carried out the shooting at the Texas military post as the soldiers, including himself, were preparing to deploy to Afghanistan. He has tried to plead guilty, but military law requires a not-guilty plea in death penalty cases.

Hasan, who is paralyzed after being shot during the attack, faces a possible death sentence if convicted of the 13 counts of premeditated murder and 32 counts of attempted premeditated murder.

'Repugnent strategy'

On Wednesday, Hassan's lead standby lawyer, Lieutenant-Colonel Kris Poppe, told the judge: "It becomes clear his goal is to remove impediments or obstacles to the death penalty and is working toward a death penalty."

After only one day of evidence, the lawyers said, they could not watch him fulfil a death wish.

That strategy, Poppe argued, "is repugnant to defence counsel and contrary to our professional obligations".

Hasan gave a brief opening statement during the trial's first day, that included claiming responsibility for the attack and announcing his commitment to jihad, or the Islamic holy war, against the US.

He posed no questions to most witnesses and rarely spoke. On one of the few times he did talk, it was to get on the record that the alleged murder weapon was his, even though no one had asked.