U.S. Secretary of State Hillary Clinton left South Sudan late last week with assurances that disputes with the world's newest nation and Sudan would be resolved. The sides they would settle issues over oil and work on addressing ill-defined borders separating the countries.
Washington has expressed frustration with lingering violence in the region, where both governments are suspected of supporting paramilitary forces.
The McClatchy news service reported that South Sudan's President Salva Kiir sent a personal letter to the U.S. president apologizing for rebel groups. The letter, U.S. officials who spoke with the news service on condition of anonymity said, said Kiir didn't know about military support for rebel groups.
"Kiir said he was working to lessen the support," the report from McClatchy said.
South Sudan's Information Minister Benjamin Barnaba Marial was quoted by the Sudan Tribune as saying any commentary on the letter was a "creation" by McClatchy.
"The contents of the letter have not yet been released by the president," the minister said.