New Delhi - United Nations Secretary General Ban Ki-moon expressed "deep concern" over the crisis in the Democratic Republic of Congo on Friday and asked rebel General Laurent Nkunda to engage in dialogue.

During a visit to the Indian capital New Dehli, Ban urged Nkunda to stick to the ceasefire announced by the Tutsi rebel leader.

The situation in the African state was "very threatening," Ban said, stressing the UN's neutrality in the conflict. "We are trying to help," he added.

Ban said that he has been engaged in talks with Rwanda President Paul Kagame, a supporter of Nkunda, since the beginning of his visit to India on Thursday.

He also was in communication with Congo's President Joseph Kabila and Jakaya Kikwete, the president Tanzania and head of the African Union, in diplomatic efforts to resolve the crisis.

A rebel offensive in the country's North Kivu province has forced tens of thousands to flee, as aid agencies warned of a looming humanitarian crisis. (dpa)