There can be no military solution to the Libyan crisis, UN Secretary General Ban Ki-moon said in a statement circulated by his press service.
"The secretary general calls on all parties to exercise extreme caution in their actions, in order to minimize any further loss of civilian life," the statement said.
"A ceasefire that is linked to a political process which would meet the aspirations of the Libyan people is the only viable means to achieving peace and security in Libya," Ban said.
An uprising which began in Libya in mid-February against Muammar Gaddafi's forty-year rule has already claimed thousands of lives, with Gaddafi's troops maintaining their combat capabilities despite NATO airstrikes against them.
Hundreds of thousands of people have left the country since February.
An international military operation "to protect civilians" in Libya began on March 19 following a UN resolution and has been extended until September.
