Representatives of key Western powers also highlighted the possibility of establishing a no-fly zone in Libya - part of growing campaign to break strongman Moammar Gadhafi's grip on power.

British, French and US officials were working on a draft text that includes language on a no-fly zone, diplomatic sources at the United Nations told CNN.

The language in the text will deal with triggers rather than timelines for taking such a step, one diplomat noted. If gross violations of human rights are committed, the diplomat added, the elements of the text could be quickly turned into a resolution.

Any resolution on military intervention in Libya, however, would be subject to a vote by the 15 members of the UN Security Council. Such intervention could face sharp criticism from Russia and China, who rarely approve of such measures.

"The violence that's been taking place and perpetrated by the government in Libya is unacceptable," US President Barack Obama said at the White House. Moammar Gadhafi's government "will be held accountable for whatever violence continues to take place there."

Obama stressed that NATO is considering a wide range of responses - including military options - for dealing with the crisis.

Death toll estimates from the conflict have reached as high as 2,000 people. Roughly 200,000 people have fled Libya, with nearly equal numbers going to Tunisia and Egypt, according to the United Nations.