WASHINGTON (AFP) - A planned reduction to the US military's footprint in Africa would not impact Army operations across the continent, the head of the US Army in Africa said on Tuesday (Dec 4).

The Pentagon last month announced it would trim about 10 per cent of the 7,200 US troops in Africa as part of a broader shift in focus towards "Great Power" competitors such as China and Russia.

Major General Roger Cloutier, whose command includes about 2,000 soldiers working in approximately 40 African nations, said some partner militaries had expressed concerns when they learned of what the Pentagon calls "optimisation".

"They're concerned, when (they) hear that," Cloutier told AFP.

"It could be confused as somehow the United States is withdrawing from Africa, and that's not the case. I can tell you that we are more involved than we've ever been."

Unlike special operations forces that sometimes see combat against militant groups, such as in Somalia, soldiers from Cloutier's command work across Africa to provide training and assistance to partner nations, as well as other forces such as UN peacekeepers and the French in Mali.

Cloutier, who started his job about three months ago and was previously chief of staff at Africa Command, garnered international attention this year when he led a probe into the deaths of four American soldiers and four members of Nigerien partner forces who were killed in a militant ambush on October 4, 2017.

Cloutier said he has incorporated lessons learned from the incident, which saw the US troops and Nigeriens fatally exposed without backup, into every operation under his command.

"I can tell you that there's been significant improvement in the way operations are done," he said in an interview at the Pentagon.

"Every time you know our personnel are operating on the continent, there's a much more thorough review of where you're going, what you're doing, who are you taking with you, what are the contingency plans associated, so a lot more focus on that."

With extremist organisations including the Islamic State group and Al-Qaeda affiliates cropping up across various African nations, the US military hopes its training and insights will bolster local armies to fend off a growing threat.

"We're there in a preventative capacity," Cloutier said, "trying to get left of the crisis and trying to build those capacities in the African armies so they can they can resolve their own issues".

Cloutier said such relationship building is "a generational approach".

"It's consistent engagement over time," he said.

US Army Africa is headquartered in Vicenza, Italy.