Sudan border clashes: African Union, UN, call for peace
The African Union (AU) is calling on Sudan and South Sudan to abide by a plan that will see both parties pull forces out of a disputed border area.
A senior AU official called for hostilities to cease in areas bordering lucrative oil fields.
The United Nations Security Council has also called for an end to aerial bombardments by Sudanese forces.
South Sudan's President Salva Kiir has said that Sudan has "declared war" on his country.
Recent clashes between Sudan and newly independent South Sudan over the Heglig oil field and nearby towns have raised fears of a return to war.
Meanwhile, South Sudan's government says 17 prisoners of war from Sudan will be released on Wednesday in response to diplomatic efforts by Egypt.
Outlining details of a proposed peace deal, AU official Ramtane Lamamra said the African Union would take "appropriate measures" if either country failed to implement the proposed plan.
He said the AU wanted both parties "formally conveying their commitment" to peace within 48 hours.
And he said both Sudanese and South Sudanese forces should pull out of the disputed area of Abyei, near Heglig, within two weeks.
South Sudan's information minister said the African Union needed external assistance to solve the crisis.
"The African Union has not done what it is supposed to do, they are talking now of a road map," Barnaba Benjamin told the BBC's Network Africa programme.
"We have been prepared for this road map, we were ready to sign the citizenship agreement, we were ready to sign the agreement on the demarcation of borders, but the Sudanese government walked away on the day of the signing and the next day they attacked us in our position.
"So that's why we think that countries like Egypt and its influence within the Arab League, its influence at the African Union can also play a positive role."
South Sudanese President Salva Kiir is cutting short his visit to China due to "domestic issues", AFP news agency quoted a Chinese official as saying.
China, a major buyer of oil from both Sudan and South Sudan, has urged both parties to show restraint in the conflict.
The UN Security Council also demanded the cessation of violence and said it will consider what steps to take in order to prevent all-out war.
The Security Council last week discussed the possibility of imposing sanctions on the two countries if the violence did not stop.
Susan Rice, the US ambassador to the United Nations said: "We strongly condemn Sudan's incursion into South Sudan and, in particular, its heavy aerial bombardments of civilian areas and infrastructure, and we call for the immediate cessation of hostilities.
"We recognise the right of South Sudan to defend itself and urge South Sudan to exercise maximal restraint in its reaction to Sudan's attacks."
In January, South Sudan shut down oil production, which provides 98% of its revenue, after Khartoum impounded South Sudanese oil shipments amid a dispute over transit fees.
South Sudan took most of the former united Sudan's oil reserves when it seceded in July 2011 but relies on pipelines to seaports in Sudan to export it.
Independence came as part of a peace deal to end two decades of conflict in which some 1.5 million were killed.