The faithful sang and danced as they waited in the scorching heat to catch a glimpse of the new cardinal. Senior government and Catholic Church officials including Vice President James Wani Igga were part of the crowd.
The cardinal said his appointment demonstrates that the South Sudan church has matured and called on all citizens to love and forgive one another.
"It is no more a young church because we have celebrated one hundred years of faith and that faith the Holy Father has seen it. As we come together, let us put God ahead of us because we have a lot of things to do together," Ameyu said. "Let us work for peace that puts each one of us together and able to say to my brother that you are my brother and to my sister that you are my sister because we have one father, God."
Ameyu, two other African Catholic Church leaders from South Africa and Tanzania are among 21 cardinals installed by Pope Francis in late September.
The cardinal said his appointment also means a new page has turned for war-torn South Sudan.
"We are a nation that is regarded as war mongers because we have been fighting all these 50 years without turning back. Today is a chance that each and every one of us should look at his or her own heart and say my dear brother, I have forgiven you from the bottom of my heart," Ameyu told the faithful.
Regina Paul, a Catholic follower, said she sees the appointment of Ameyu as a blessing for the world’s youngest country.
"It a great day. It is for the first time for South Sudan to have a cardinal. It means a lot. It means we have to change. We need peace. We need this day to change all of our lives," Paul told VOA.
Rita Igale, another Catholic faithful, called on the cardinal to push South Sudanese leaders to restore peace.
"We need blessing from our cardinal. We need him to bring for us peace. And let the leaders of South Sudan revise their hearts so that they can live in peace and so that they can bring for us real peace, and I am very happy for this day," Igale said.
Pope Francis paid a historic visit to South Sudan in February in what was described as an ecumenical pilgrimage of peace.