The Security Council recently unanimously adopted a resolution slapping sanctions on the Libyan regime, which includes a complete arms embargo, an asset freeze and a travel ban on the country's leadership and an immediate referral to the International Criminal Court.
"The Secretary-General discussed the increasingly troubling humanitarian situation, in particular the plight of migrant workers," a statement from the UN said.
Ban also called on the authorities to "ensure the safety of all foreign nationals and unhindered access for humanitarian organisations to people in need."
Kusa has agreed to the immediate dispatch of a humanitarian assessment team to Tripoli, according to the UN.
The statement also said that Ban "is deeply concerned about the fighting in western Libya that "threatens even more carnage in the days ahead.... and civilians are bearing the brunt of the violence."
The Secretary-General has called for "immediate halt to the government's disproportionate use of force and indiscriminate attacks on civilian targets" and warned that those committing war crimes would be held accountable.
Last week, the chief prosecutor of the ICC, Luis Moreno-Ocampo, announced that he will investigate war crimes allegedly committed by Libyan leader Moammar Gaddafi and his loyalists.
Ban has appointed Abdelilah Al-Khatib, the former foreign minister of Jordan, as his special envoy to Libya, to consult with the Libyan leadership on the humanitarian situation as well as the larger fallout of the ongoing crisis.