What should the UK do about the unrest in Libya?
The US has said the UN should consider more than just a no-fly zone over Libya, amid Security Council division on a draft resolution.
US ambassador Susan Rice said a no-fly zone would only bring limited help. She hoped for an early vote on a draft.
Russia expressed concern at some of the implications of the proposals and put forward a counter-resolution.
Forces loyal to Col Gaddafi are taking ground from rebels, who say they fear “genocide” without swift UN action.
On Wednesday, the International Committee of the Red Cross withdrew from the rebel-held city of Benghazi, in eastern Libya, saying it feared an imminent attack by Col Gaddafi’s forces.
Government forces say they have captured Ajdabiya, the last town before Benghazi, but the rebels deny this.
The UN Security Council on Wednesday undertook lengthy and difficult negotiations over a resolution aimed at authorising a no-fly zone.
The US has previously been cool on the effectiveness of such a zone, but Ms Rice said further measures were now needed.
“The US view is that we need to be prepared to contemplate steps that include, but perhaps go beyond a no-fly zone, at this point, as the situation on the ground has evolved and as a no-fly zone has inherent limitations in terms of protection of civilians at immediate risk.”