JUBA, South Sudan — Secretary of State Hillary Rodham Clinton urged leaders of South Sudan and their counterparts in the north Friday to quickly reach agreements on oil revenue and other pressing issues to resolve festering differences that threaten to reignite a decades-long conflict.
Clinton flew to South Sudan’s capital, Juba, for a brief visit to congratulate the nascent nation on its anniversary and offer US support, but, more importantly, to emphasize the urgency of ending disputes with Sudan over oil and territory. Those disputes have led to clashes between the two countries that many fear could crater the 2005 peace deal that ended what was then Africa’s longest-running civil war.
‘‘While South Sudan and Sudan have become separate states, their fortunes and their futures remain inextricably linked,’’ Clinton said at a press conference. ‘‘Now it is urgent that both sides, north and south, follow through and reach timely agreements on all outstanding issues. The people of South Sudan expect it.’’
The two sides had faced a Thursday UN Security Council deadline to reach agreement on the issues or face possible sanctions, but the council deferred action until at least Wednesday.
Before Clinton’s visit, a senior US official, speaking on condition of anonymity because he was not authorized to discuss the matter publicly, said Clinton would express concern about a ‘‘lack of movement’’ in resolving the situation but also reaffirm America’s strong support for South Sudan, the world’s newest nation.
The United States was instrumental in helping to negotiate the 2005 peace agreement, and the official said Washington is ‘‘heavily invested’’ in its success.
The disputes, particularly over oil revenue, have led to severe economic problems in both Sudan and South Sudan. But the South, which celebrated its first year as an independent nation last month, is in a more precarious situation as it is more dependent on outside assistance.
Clinton urged the two sides to reach an interim agreement on oil profits so revenue would start flowing again.
‘‘A percentage of something is better than a percentage of nothing,’’ she said at a press conference with Nhial Deng Nhial, South Sudan’s foreign minister.
Clinton also said an agreement could give South Sudan time to look at the feasibility of building another pipeline that would bypass Sudan.
Nhial said his government wants the United States to continue its support and to exert pressure on Sudan to accept the proposals South Sudan has made.
‘‘This is a delicate moment,’’ Clinton said, ‘‘because you have made a strong, irrefutable point about your right to more resources and now we need to get those resources flowing again so that you can benefit on what is the natural treasure of South Sudan.’’
Clinton spoke after a meeting with President Salva Kiir.
The mostly black African tribes of South Sudan and the mainly Arab north battled two civil wars over more than five decades, and some 2 million died in the latest war, from 1983-2005. It ended with the 2005 peace pact that led to last year’s independence declaration for South Sudan.
Though the breakup was peaceful, hostilities flared earlier this year.
South Sudan inherited about three-quarters of the region’s oil, but shut down its oil industry in January after accusing Sudan of stealing oil that the South must pump through Sudan’s pipelines. That decision has cost both governments dearly in lost revenue.
In April, the two countries’ militaries fought over the disputed, oil-rich region of Heglig. South Sudan troops took over the town from Sudanese forces, but that offensive maneuver was condemned by world leaders. South Sudan says it then retreated from Heglig, though Sudan says its forces pushed the South out.
Also on Friday, China’s state media criticized Clinton for comments she made earlier in the week in Senegal criticizing China’s investments in Africa.