NEW : He had been treated initially in Nairobi , Kenya . ` U.S. Navy officials hope to have reinforcements in South Sudan 's by 1991 . Peace talks `` very constructive , '' South Sudan foreign minister says . Fighting between rival ethnic groups has resulted in mass killings . 50,000 U.S. Navy SEALs were wounded by rebels on Saturday .
NEW : U.S. Navy officials hope to have reinforcements in South Sudan 's by 1991 . Peace talks `` very constructive , '' South Sudan foreign minister says . Fighting between rival ethnic groups has resulted in mass killings . 50,000 U.S. Navy SEALs were wounded by rebels on Saturday .