"I urgently call for an immediate ceasefire in these areas to allow humanitarian assistance to reach many thousands of displaced persons."
But hostilities did not appear to be easing as a rare night gun battle erupted on Tuesday just north of Goma.
Colonel Jean-Paul Dietrich, a UN peacekeeping spokesman, said mortars were used during the nearly one-hour battle near Kibati and the UN had urged the two sides to move farther apart to prevent the conflict from escalating.
More peacekeepers urged
Ban also called on the Security Council to send 3,000 more troops to strengthen the 17,000-strong UN peacekeeping mission, Monuc, in the Democratic Republic of Congo.
"Monuc has been working hard to protect peace but they have been overstretched. Therefore, we urgently need additional resources," he said.
General Babacar Gaye, the commander of Monuc, said his forces were doing their "very best to protect the population" but added: "[It] is a very tricky issue because we are stretched to the limit."
Even as members of the Security Council met to discuss the situation behind closed doors on Tuesday, aid agencies accused it of falling short of promises.
But council members say no action is likely before they see the secretary-general’s report on the situation, which is not due until November 19.
The Southern African Development Community (Sadc) has promised to send military experts and equipment to the Congolese government.
David Monyae, a political analyst, told Al Jazeera said it was "shocking" that the UN has been caught offguard by the conflict.
"There is a need for an urgent humanitarian intervention and the question of deploying 3,000 UN peacekeepers is just piecemeal," he said.
"You need tens of thousands moving in, this country is much bigger than Western Europe. Sadc also has to intervene and make sure people are protected.
"Unco-ordinated interventions are making this conflict more complex. You have a democratic government that must be protected at all costs."
Also on Tuesday, the UN accused government troops of widespread looting and human rights abuses against civilians in several towns in the eastern part of the country.
A spokesman for Monuc said on Tuesday that violence against civilians, including the rape of women, had spread and was continuing.
The pillaged towns, including Kaina and Kirumba, are strategically located in the north of North Kivu province, where Nkunda loyalists control much of the territory following an offensive launched on August 28.
Mohammed Adow, Al Jazeera's correspondent reporting from Kibati, said the UN needed at least 2,000 more troops to help supplement the overstretched force.
The 800 peacekeepers in Goma were not enough to stop the rebels from marching into the provincial capital should they choose to, Adow said.
Meanwhile, the World Health Organisation (WHO) warned on Tuesday that "all the ingredients are there" for a cholera epidemic.
"We have a serious risk of having a big cholera epidemic in this part of the world ... We have a population that is on the move, an unstable security situation and a population that does not have access to safe water and proper sanitation," Dr Claire-Lise Chaigot of the WHO told Al Jazeera from Geneva.
Chaigot said that fresh fighting would further hinder efforts to get aid and medical supplies to people already hard to reach.
Monyae added: "There is a need to investigate who is benefiting. There are countries, in the West and in Africa, private companies and individuals that are benefiting out of this conflict, so the media must step in and expose the individuals who are causing such havoc.
"Former colonial powers tend to focus on Zimbabwe and keep quiet on this country in which they are benfiting from mineral riches of the Congo."