South Sudan's President Salva Kiir will visit Khartoum on Tuesday, both nations confirmed, ahead of Khartoum's Friday deadline to shut economically vital oil pipelines over the South's alleged rebel support.
"I can confirm he will arrive on Tuesday," Emad Sayed Ahmed, press secretary to Sudan's President Omar al-Bashir, told AFP on Sunday.
He said the two leaders will discuss "all the joint issues" during the visit, without giving further details.
A South Sudanese embassy official also confirmed Kiir's visit.
In June Sudan said it was freezing nine security and economic pacts with the South, and threatened to shut the oil pipelines linking landlocked South Sudan with the Red Sea export terminal.
The decision came after Bashir warned the South over backing insurgents, who analysts said had humiliated the authorities with their attacks.
Khartoum has twice extended its deadline to shut the pipelines, which are now threatened with closure from September 6.
Despite the threat, oil has continued flowing for export.
The deadline extensions followed an appeal from the African Union. The regional group asked for more time to investigate allegations -- by both Sudan and South Sudan -- that they are supporting rebels on each other's territory.
Kiir last visited Khartoum in October 2011.
The two leaders held a summit in the South's capital Juba in April, during a period of easing tensions after months of intermittent border clashes, and before Khartoum's abrupt threat to close the pipelines.