The International Committee of the Red Cross announced it recognized South Sudan's charter, making it the 189th member of the International Red Cross and Red Crescent Movement.
"Recognition of the South Sudan Red Cross is a landmark for the movement," Philip Spoerri, director for international law and cooperation at the ICRC, said in a statement. "We are pleased to welcome this new national society and are confident that it will carry out the mission of our movement, which is to prevent and alleviate human suffering wherever it may be found."
The ICRC said last week it was growing concerned about the status of civilians in Jonglei, South Sudan's largest state.
A U.N. report this spring said at least 85 people were killed in Jonglei when armed bandits attacked cattle grazers. The ICRC said "thousands" of civilians have fled the area because of continued violence.
South Sudan became an independent country in 2011 under the terms of a peace deal that ended Sudan's civil war. Border conflicts, ethnic rivalries and disputes over oil have threatened the fragile peace.