South Sudanese Petroleum and Mining Minister Stephen Dhieu Dau announced production restarted at the Tharjath oil fields in Unity state, the Africa Review reported.
"We are pumping from today," Dhieu said. "The production is to resume from Tharjiath and will be followed by other oil fields as from today."
South Sudan, which officially split from Sudan in 2011, has also agreed with Sudan to ship oil across the countries' border, the BBC reported.
The South took nearly 75 percent of Sudan's oil production when it seceded two years ago and in turn, Sudan charged the South high fees for exporting oil.
South Sudan, which is landlocked and relies on Sudan's ports, previously said the charges were too high.
Dhieu said the agreement between South Sudan and Sudan should be seen as a sign of peace between the two countries.