South Sudan, which declared its independence from Khartoum on July 9, has become a full fledged member of the United Nations.
The decision was passed by a session of the UN General Assembly on Thursday.
South Sudan has become the 193rd country recognized by the United Nations and the 54th UN member state in Africa.
The UN Security Council recommended UN membership for South Sudan on Wednesday.
South Sudan's vice president, Riek Machar, expressed his country's profound gratitude for the action.
"It is our deepest and most sincere wish to resolve all outstanding matters between north and south swiftly and peacefully," Machar said. "We remain committed to working out our differences through dialogue and in a spirit of cooperation."
The African tribes of South Sudan and the mainly Arab north fought two civil wars over more than five decades. About 2 million people died in the latest war, from 1983-2005.
