(CNN) — The US troops attacked in Niger were on their way back to their operating base when they were ambushed by 50 ISIS fighters, according to Joint Chiefs Chairman Gen. Joseph Dunford, who provided a timeline of the attack on Monday.

Four US and five Nigerien soldiers were killed and two Americans were wounded in the attack that occurred on October 4, but details of what happened remain murky more than two weeks after the incident as investigators work to determine precisely what happened, a US official has told CNN.

During the Pentagon briefing Monday, Dunford clarified that the US troops requested additional support about an hour after the firefight began.

Remotely piloted aircraft arrived overhead within minutes of the request for help. French Mirage jets arrived on the scene approximately one hour later — two hours after the troops made initial contact with enemy forces.

“It’s important to note when they didn’t ask for support for that first hour, my judgment would be that that unit thought they could handle the situation without additional support,” Dunford said. “And so well we’ll find out in the investigation exactly why it took an hour for them to call.”

Dunford said there is no indication that the US troops were operating outside their orders at the time of the ambush.

“I don’t have any indication right now to believe or to know that they did anything other than operate within the orders that they were given,” Dunford said. “That’s what the investigation’s all about. So I think anyone that speculates about what special operations forces did or didn’t do is doing exactly that, they’re speculating.”

Still, Dunford said the military will be investigating if the planned reconnaissance mission changed.

“It was planned as a reconnaissance mission. What happened after they began to execute, in other words, did the mission change? That is one of the questions that’s being asked. It’s a fair question but I can’t tell you definitively the answer to that question. But, yes, we’ve seen the reports, we’ve seen the speculation,” he said.

One US soldier, Sgt. La David Johnson, was separated from his 12-member team as it was ambushed by 50 ISIS fighters, and his body was recovered 48 hours later nearly a mile away from the central scene of the ambush in Niger, four administration officials familiar with the early assessment of what happened had told CNN on Friday.

Dunford said Monday that he could not definitely confirm reports that Johnson was found nearly a mile away but that those details would come to light as part of the investigation.

“I think we owe the families and American people transparency,” Dunford said.

The Pentagon is still looking at the exact circumstances of how and when Johnson became separated, but is emphasizing that the search for Johnson began immediately and dozens of US forces were quickly moved to Niger’s capital Niamey to be ready to go into the field, which some did.

Joint Staff Director Lt. Gen. Kenneth F. McKenzie told reporters last week that US, French and Nigerien forces “never left the battlefield” until Johnson was found.

Experts working for US Africa Command are trying to establish an hour-by-hour timeline of what happened as part of a comprehensive investigation that includes all the military branches and elements of US intelligence agencies that were involved in the mission.

CNN previously reported that the French Mirage jets that arrived overhead within 30 minutes of the firefight to fly low passes in an attempt to disperse the attackers did not have permission to drop bombs.

But on Friday, US officials said that French jets did have authority to bomb but did not because pilots could not readily identify enemy forces in this firefight and did not want to risk hitting US and Nigerien troops.

This Pentagon briefing with Dunford offers a particularly striking change of tone from the public response of the Trump administration in the wake of the Niger attack.

A White House official described Monday’s briefing as an intentional effort to move beyond the heated rhetoric from all sides on this — including from the West Wing.

An official said White House chief of staff John Kelly and people throughout the West Wing would be watching the briefing.

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