By Andrew Heavens
KHARTOUM (Reuters) - Sudan's President Omar Hassan al-Bashir vowed to fight northern rebels and boycott future international peace talks on Thursday, two days before the secession of the south of his country.
South Sudan is due to declare independence on Saturday, a long-awaited separation it won in a 2005 peace deal that ended decades of civil war.
Bashir, who will lead north Sudan after the split, said he would travel to the southern capital Juba on the south's independence day and promised friendly relations.
"We gave them a complete state with oil. All they need to do is to switch on the engine," he said.
Bashir's presence in Juba will reassure diplomats who are worried that unresolved disputes over the details of the secession -- most importantly how oil revenues will be shared -- could spark another north-south conflict.
But the aggressive tone of most of Bashir's speech to supporters in the north's White Nile state signaled he would not countenance similar deals with insurgents inside his own territory.
The northern government is fighting armed groups demanding more autonomy in Darfur and Southern Kordofan - both northern regions that border south Sudan. Analysts have said the south's successful independence would embolden other rebels.
Bashir said he would negotiate with Southern Kordofan rebels only once security had returned to the region.
"After all this backstabbing, betrayal, destruction, killing and displacement of civilians (in Southern Kordofan), they bring us an agreement and tell us to establish a political partnership," Bashir said in a speech translated by BBC Monitoring.
Bashir said he would see through the ongoing peace talks with a small groups of Darfur rebels in Qatar's capital Doha and would reach a final settlement later this month.
"We have decided that there will be no negotiations outside Sudan again, no talks outside Sudan and the ongoing talks in Doha will be the final talks outside Sudan with anyone carrying weapons," he said, as the crowd chanted.
"Anyone who takes up arms against us will be dealt with decisively." Bashir has been indicted by the ICC over war crimes charges stemming from fighting in the Darfur region.
Northern and southern officials have been meeting in Ethiopia to discuss a possible ceasefire in Southern Kordofan and other issues. But southern officials told Reuters these were suspended earlier this week when Bashir objected to the presence of U.N. mediators.
"I will travel to Juba in two days to congratulate them on their new state and wish them security and stability," Bashir said in the televised speech.
Sudan stands to lose about a third of its territory and around three-quarters of its oil reserves when the south leaves, and some in the north regard the loss as a national humiliation.
U.N. Secretary-General Ban Ki-moon called for a peaceful secession and an immediate end to clashes in Southern Kordofan.
"We have to really help them so that South Sudan will be able to carry out the very difficult challenge of the future of their country," Ban told reporters in Geneva.
"It is critical that this transition takes place peacefully and once again I call for an immediate cessation of hostilities in South Kordofan."
Heavy gunfire and bombardments were heard in Southern Kordofan every day from June 30 to Tuesday, the United Nations said in a report on Thursday. Fighting began in early June.
Media access is restricted and government authorities have barred the United Nations and aid groups from working outside the state capital Kadugli.
Aid officials, speaking to Reuters on condition of anonymity, said they were worried about what would happen to civilians after the withdrawal of the U.N. Mission in Sudan (UNMIS) and its peacekeepers on July 9 -- the south's independence day and the end of the mission's mandate.
"There is a really serious scaling up of military hardware and supplies," one source said.
"There are Antonovs flying overhead in the late evenings and in the morning. Heavy machinegun fire. The odd use of artillery and mortars and the dropping of bombs in the surrounding hillsides in Kadugli. That is our staple diet."
North and south Sudan still have to settle a list of unresolved issues, including the position of their shared border, and how they will split debts and manage oil revenues.
The south currently has to transport its oil through northern pipelines but had not agreed how it will pay for the service. A U.N. peacekeeping force, provided by Ethiopia, would soon deploy in the disputed area of Abyei, Ban said.
South Sudan's parliament passed the region's new transitional constitution overnight, the government's spokesman said on Thursday, two days before southern President Salval Kiir signs it into law on independence day.
Critics have said the constitution gives too much power to Kiir and paves the way for one-party rule.
(Additional reporting by Ulf Laessing and Khaled Abdelaziz in Khartoum, Jeremy Clarke, Alex Dziadosz and Berenika Stefanska in Juba and Aaron Maasho in Addis Ababa; Editing by Michael Roddy)