Spokesman said Bosco Ntaganda tried to 'influence the chain of command' but went too far in challenge to Sultani Makenga.
Bosco Ntaganda surrendered in Kigali earlier this week.
A State Dep't official says the U.S. hopes Rwanda will facilitate Bosco Ntaganda's transfer to the ICC.
ICC-wanted warlord Bosco Ntaganda had lived for years as a fugitive.
Villagers say they saw a half dozen trucks with Rwandan soldiers cross into Congo to lend support to troops led by a wanted rebel leader.
Should help avoid jeopardizing the delicate peace process.
The firing of the general indicates that Congo is getting tough on its army.