President Obama notified Congress today that he is sending about 100 U.S. troops to central Africa to help battle a rebel group known as the Lord's Resistance Army.

The troops arrived in Uganda this week and will ultimately be deployed to South Sudan, the Central African Republic and the Democratic Republic of the Congo, Obama said in a letter to congressional leaders.

The Lord's Resistance Army is accused of a two-decade spree of murder, rape and kidnapping.

The troops will be combat-equipped, but will fight only in self-defense, Obama said,

Instead, they will serve largely in an advisory role to remove LRA leader Joseph Kony "from the battlefield."

From Obama's letter: