ADDIS ABABA, Ethiopia — Sudan says significant progress is being made in talks with South Sudan as negotiations over their shared border entered a fourth day Wednesday.

Both Sudan President Omar al-Bashir and South Sudan President Salva Kiir are skipping the U.N. General Assembly in New York to stay at talks being held in Ethiopia's capital. The two leaders have met since late Tuesday but have not yet achieved a breakthrough agreement.

El-Obeid Morawah, a spokesman for Sudan's Foreign Ministry, said late Tuesday that obstacles remain in the talks over the Abyei region and a buffer border zone. He said the talks are hard but that there is political will on both sides to reach resolution.

South Sudan broke away from Sudan last year after decades of war. Their shared border was never totally agreed upon.