South Sudan says it will pull its forces from the Heglig oil fields it seized from Sudan, following several days of growing international pressure.

Speaking to reporters Friday in the south's capital, Juba, a government spokesman said President Salva Kiir has ordered the withdrawal of troops from Heglig, also known as Panthou.

On Thursday, U.N. Secretary-General Ban Ki-moon termed the south's occupation of Heglig an illegal act that infringed on the sovereignty of Sudan.

Sudan's President Omar al-Bashir has threatened to go to war with South Sudan and teach the south's government a “lesson by force.”

The countries have been fighting along their disputed border but the U.S. special envoy to Sudan, Princeton Lyman, said Thursday that both sides want to avoid a larger conflict.

“In the discussions I have had in both Khartoum and Juba, I can say with confidence that virtually everyone I have talked to has said, 'Look we don't want to go to all-out war with the other We need to find a way out.”

The two Sudans have been unable to resolve disputes over borders, oil, and citizenship issues stemming from the south's independence last July.