Christian and Muslim leaders in the Central African Republic have accused foreign states of complicity in a May 1 gun and grenade attack on a Catholic Mass.
Bishop Gassis' visits came in the middle of decades of on-again, off-again fighting between the central government and several rebel movements in the South and other peripheral areas of the country.
In April scores have died in a series of attacks and assassinations in Mexico, the Philippines and Nigeria. Catholics at prayer during Mass have been targeted in a number of attacks.
Since civil war began to rip apart South Sudan's fragile democracy in 2013, roughly one-third of the country's 12 million people have been forced to flee their homes.