By Hereward Holland
JUBA (Reuters) - South Sudan's President Salva Kiir will visit Sudan this month to witness with his counterpart Omar Hassan al-Bashir the first shipment of oil from the south after a 15-month shutdown, an official said on Friday.
In March, the African neighbors agreed to resume oil exports from landlocked South Sudan through Sudan and defuse tension that has plagued them since South Sudan seceded in 2011.
Kiir's planned trip signals a further thaw in relations following a landmark visit by Bashir to Juba in April, his first since the south gained independence in July 2011 under a 2005 peace deal ending decades of civil war.
South Sudan resumed oil production last month, although industry analysts say it may take at least a month for the oil to reach the export terminal at Port Sudan, on the Red Sea.
Kiir will visit both Khartoum and Port Sudan, said Barnaba Marial Benjamin, South Sudan's government spokesman.
"When (the oil) has reached Port Sudan, that is when the two presidents will go to see the first oil come out of the pipeline, within May probably," Benjamin told Reuters.
There was no immediate comment from Sudan but local newspapers have reported that Kiir will come in May.
Prior to the shutdown, South Sudan produced at least 300,000 barrels per day, but observers say it may take at least a year to regain such levels.
Damage caused by cross-border skirmishes a year ago means South Sudan can only gradually ramp up production in its Unity State oil fields, which is mixed to produce Nile Blend, a light, sweet, waxy crude.
In the coming days, South Sudan plans to reopen its oil fields in Upper Nile State, which produce Dar Blend, a heavy, sour crude.
Industry experts say Dar Blend production will start at around 50,000 barrels per day, quickly rising to at least 150,000 bpd, while Nile Blend is likely to remain at around 30,000-40,000 bpd for at least six months.
(Reporting by Hereward Holland; Editing by Ulf Laessing and Michael Roddy)