Ban arrived at a refugee camp at Al-Fasher on Wednesday for a first-hand look at the humanitarian situation.
The secretary-general was handed a petition by a small group claiming to represent people displaced by the conflict.
It called for Ban to support a government-backed policy to encourage displaced Darfuris to return to their villages.
Mohammed Adow, Al Jazeera's correspondent in Sudan, said the visit comes amid fighting between rival Arab tribes and reports of division among anti-government groups in Darfur.
"The Arab tribes are fighting each other, but the rebel groups are also splintering. They don't share one vision for Darfur," he said.
|Mohammed Adow reports on the delivery of aid to Darfur|
Adow said that displaced people sheltering at the al-Salam camp near the town of al-Fahser were desperate to return to their homes.
"[The camp at Al-Fasher] is a place where more people are coming to, following the new fighting," he said.
"The people at the camp want to go back to the villages, restart their lives, rear livestock and grow their crops. The new conflict is not encouraging them at all."
After his visit to the camp, Ban is due to return to Khartoum on Thursday, ahead of meetings with Sudan's neighbours Chad and Libya.
The UN secretary general said he had urged Omar Hassan al-Bashir, Sudan's president, to help in the planned deployment of a hybrid UN-AU peacekeeping force.
Ban said that al-Bashir had replied that his government would provide "all necessary administrative and logistical support".
"Time is of the essence. The government's co-operation is essential on a range of practical matters," Ban said.
During his visit, Ban is also seeking to bolster a 2005 peace deal that ended two decades of civil war in Sudan, which has become increasingly fragile of late.
The Comprehensive Peace Agreement was signed in January 2005 to end 21 years of war between the Muslim north and Christian and animist south that killed at least two million people and displaced millions more.
|Ban will address the deployment of a hybrid|
peacekeeping force for Darfur [AFP]
"It is crucially important that we implement the CPA ... it is important that the leaders of both the north and the south be fully committed," Ban said in Juba.
A senior UN official travelling with Ban said there were "worrying signals" about the implementation of the peace deal, including delays in the promised pullout of government troops from the south.
The UN official said: "There are a number of signs that show there is a need to push the CPA forward.
"Both sides have indicated their commitment to the agreement but it is important not to let it slip."
In Juba, Ban held talks with Salva Kiir, Sudan's vice-president and a former rebel leader who took over as head of the Sudan People's Liberation Army in July 2005.
In a separate development, Ban announced he has appointed Ashraf Qazi, currently UN envoy to Iraq, as his new special representative for Sudan, replacing Jan Pronk.
Ban cited Qazi's "wide and extensive diplomatic experience" in naming him to the post.
Pronk was expelled from Sudan in October 2006 for criticising the army over its conduct against Sudanese rebels.
Source: Al Jazeera and agencies