Ten bases honoring generals from the secessionist South, which lost the Civil War (1861-1865) and its struggle to preserve slavery, are in the spotlight.

Demands to rename such installations have gathered momentum in the wake of mass protests across the United States against police brutality and racism against African Americans that were sparked by the death of George Floyd in police custody.

Naming the bases for Confederate generals was a "political" decision, and renaming them must also be a political one, General Mark Milley, the chairman of the Joint Chiefs of Staff, said while testifying before a Congressional committee.

The military's concern is the "divisiveness" of the names, he said, noting that the US military is one of the institutions where minority groups are more represented.

In the army, to which the bases in question belong, 20 percent of the soldiers are black, even 30 percent in some units, Milley noted.

"For those young soldiers that go on to a base, Fort Hood or Fort Bragg or Fort whatever... they can be reminded that that general fought for an institution of slavery that may have enslaved one of their ancestors," he said.

"We also got to take a hard look at the symbology, the symbols, things like Confederate flags and statues and bases," added Milley, who had several harsh words about the Southern generals.

The Civil War "was an act of rebellion. It was an act of treason at the time against the Union, against the Stars and Stripes, against the US Constitution," he said, using the nickname for the American flag.

"And those officers turned their back on their own."

The largest military base in the country, Fort Bragg in North Carolina, bears the name of Confederate general Braxton Bragg, who is best known for losing the decisive Battle of Chattanooga in 1863.

Fort Hood, in Texas, is named after General John Bell Hood, known for suffering multiple defeats on the battlefield that -- according to historians -- he tended to blame on his subordinates.

Defense Secretary Mark Esper had indicated in early June that he'd be at least open to a "bipartisan discussion" on base renaming.

But Trump quickly shut down the idea, insisting that the bases were part of the United States' "history as the Greatest Nation in the World" and that his administration would "not even consider" renaming them.