Salva Kiir, the new vice-president of Sudan, has said he is firmly opposed to independence for the country's south.
Salva Kiir says he will work together with President Omar al-Bashir
Speaking after his inauguration in the capital, Khartoum, Mr Kiir told the BBC he wanted to see Sudan as a united country, giving the south new status.
He succeeds former rebel leader John Garang, who died three weeks after becoming vice-president as part of a deal to end 21 years of conflict.
Questions have been asked about whether Mr Kiir shares his commitment to unity.
But the new vice-president, sworn in on Thursday, told the BBC's World Today programme he was fully committed to Mr Garang's vision of Sudan as one country.
Mr Kiir said the dominant group in the Sudan People's Liberation Movement (SPLM) had always wanted to fight for a "united country on a new basis", rather than independence for the south.
Mr Garang's peace deal is a possible blueprint for ending the fighting in Sudan's western Darfur region, he said.
Mr Kiir added there could be no comprehensive peace until all Sudan's conflicts were ended peacefully and the government tackled the issues of armed groups and displaced people.
He dismissed suggestions he might fail to win the same respect as a leader as that enjoyed by Mr Garang.
"After the death of John Garang I was elected unanimously," he said.
"If I did not command that respect, the military command and the political leadership in the movement would not have elected me unanimously."
His succession to the role of vice-president followed Mr Garang's death in a helicopter crash on 30 July.
Asked whether he had suspicions about the cause of the crash, Mr Kiir said an investigation had been set up to find out exactly what had happened and attribute responsibility.
Mr Kiir said he would be able to work with members of Sudan's government - his former enemies - because they had acknowledged that people in the south had had cause for complaint.
After arriving in Khartoum on Wednesday, Mr Kiir appealed for calm after riots following Mr Garang's death left at least 130 dead.
The civil war pitted the Muslim north against Christians and animists in the south, leaving some 1.5 million people dead.
Under January's peace deal, the SPLM and the government agreed to share wealth and power.
The south is set to hold a referendum on secession in six years' time.