United Nations Chief Ban Ki-moon says Libya is facing “large” challenges, with peace and security being the top priorities.

The Secretary-General commented on Tuesday at the start of a U.N. meeting in New York of world powers deciding on Libya's future course.

The meeting comes less than a week after the U.N. Security Council voted to turn over Libya's General Assembly seat to the country's new National Transitional Council .

NTC chairman Mustafa Abdel Jalil told the group at least 25,000 people had died in the uprising that has led to NTC control of most of the country.

U.S. President Barack Obama said his administration would support Libya as its new government works to build a “free, democratic and prosperous” future.

Mr. Obama said in prepared remarks that Libya will have a “friend and partner” that will assist Libyans in developing security, providing humanitarian aid and peacefully transitioning to democracy.

Mr. Obama also added that Libya is a “lesson” in what the international community can achieve when it stands together as one against injustice.

French President Nicolas Sarkozy said there would be “ups and downs” for Libya, but “no one should want to bring back the past.” France has played a major role in the NATO-led mission in Libya.

The U.N. is preparing to deploy a political support mission to Tripoli. Mr. Ban says the mission will be comprehensive and must be “fully consistent” with Libya's needs and priorities.

In August, fighters for Libya's provisional authority overran Mr. Gadhafi's compound in Tripoli. Battles continue in a handful of strongholds of Mr. Gadhafi as the NTC develops an interim government to rule until elections are held.