Speaking to reporters in the Indian capital, New Delhi, Mr. Ban characterized the situation on the ground in North Kivu province as "very threatening."
He stressed that "this ceasefire should be kept, and the international community, African leaders - particularly those leaders in the region - should take very concrete measures so that this ceasefire can be maintained... and there should be a disengagement of the forces from there."
Recent days have seen an escalation in hostilities in North Kivu - which borders Rwanda and Uganda - between Government forces (FARDC) and the militia headed by Mr. Nkunda, known as the National Congress for the Defence of the People (CNDP).
Humanitarian agencies estimate that the clashes have sent as many as one quarter of a million people - many of whom had already been uprooted from their homes - fleeing, bringing the total number of internally displaced persons (IDPs) in North Kivu to over 1 million.
The UN peacekeeping mission in the country, known as MONUC, reported today that the situation in the provincial capital, Goma, remains calm, with no outbreak of fighting occurring over the past 24 hours.
FARDC forces have returned to the airport and taken over security responsibilities, while MONUC patrols last night on Goma's streets aimed to reassure civilians. Nearly two dozen people were killed two days ago in the city, including eight government soldiers who were shot while taking part in looting. The UN is also investigating reports of rape.
On the diplomatic front, the Secretary-General said today that he has been "heavily engaged in this process," having been in contact with leaders in Africa, the European Union (EU) and the United States. They include DRC President Joseph Kabila, Rwandan President Paul Kagame, Tanzanian President Jakaya Kikwete, who is also the President of the African Union (AU), and Chairman Jean Ping of the African Commission.
He has also spoken to US Secretary of State Condoleezza Rice and Foreign Secretary David Miliband of the United Kingdom, among other others.
Mr. Ban has dispatched two of his senior aides to the region - Assistant Secretary-General for Peacekeeping Operations Edmund Mulet to the DRC and Assistant Secretary-General for Political Affairs Haile Menkerios to Rwanda.
His top envoy to the DRC, Alan Doss, travelled to Goma today to assess the situation and to meet with local authorities and aid workers.
Mr. Doss, who serves as the Secretary-General Special Representative and head of MONUC, was part of a delegation that also included Jendayi Frazer, US Assistant Secretary of State for African Affairs, and Ali Bongo, AU Representative to the DRC.
MONUC has taken action on the ground to protect civilians, but is limited by the security concerns, Mr. Ban told journalists.
The current ceasefire has provided a window for humanitarian agencies to provide assistance to those in need, and "now, there should be a political process going on," he said.
The UN Office for the Coordination of Humanitarian Affairs (OCHA) reported that most of the relief workers besieged in Rutshuru and Kiwanja have been evacuated by MONUC helicopters.
MONUC - which has been mandated by the Security Council to protect civilians - has fewer than 1,000 troops in Goma, which has a population of some 1 million, and Mr. Ban acknowledged that there is a limit to what UN forces can do in the region.
He stressed that the "UN is not a party of belligerents," voicing concern over demonstrations and physical attacks arising from "misunderstandings" on the part of Congolese civilians against the peacekeeping mission.
The UN "is there to keep peace and stability," the Secretary-General underscored, adding that the world body is trying to help and diffuse the situation.