U.S. Secretary of State Hillary Clinton is urging Sudan and South Sudan to resolve bitter disputes that have brought the countries to the brink of war.

Clinton spoke to reporters Friday during a brief visit to the southern capital, Juba, where she met with South Sudanese President Salva Kiir.

She said Sudan and South Sudan “will need to compromise” to settle remaining issues between them, and specifically urged the sides to reach an agreement on sharing oil revenue.

South Sudan shut down all oil production in January because of a dispute with Sudan on fees charged to use northern pipelines. Clinton said Friday that while the two Sudans have become separate, their futures and fortunes are permanently linked.

The two countries were facing a U.N. warning to resolve their disputes by August 2 or face possible sanctions. The deadline expired Thursday.

A U.S. State Department official traveling with Clinton on her African tour said the bitter divisions over territory and oil threaten to wreck the economies of both nations.

The sides clashed along their border in April, raising fears of all-out war.

Clinton is on an 11-day tour of Africa with scheduled stops in at least six nations.

Later Friday, she meets in Uganda with President Yoweri Museveni. Clinton will use the talks to discuss Uganda's role as a key U.S. partner in regional security, as well as to encourage stronger democratic institutions and human rights.