Libya’s new prime minister said failure was not an option, in his first address after being chosen to lead the country.
Abdul Hamid Dbeibah, 61, a businessman and engineer, promised to create an inclusive and transparent administration to bring about unification and democratic elections.
Mr Dbeibah has 21 days to form a Cabinet and then three weeks to present its programme.
He hailed the new political map to end Libya's conflict and hold parliamentary and presidential elections in December this year.
Mr Dbeibah said the selection of an interim leadership on Friday was a “symbol of the victory of national unity, reunification, peace-building and achieving the desired democracy”.
“Failure in this sensitive stage of the history of Libya and its people is not an option,” he said.
“And therefore, I invite everyone without exception to rally around this government to start the serious work to rebuild our country on a solid basis.”
Mr Dbeibah said his government would support women, youths and local governments, and promote freedom of opinion.
He was selected as interim prime minister in a vote held by a forum of 75 Libyan delegates at UN-led talks outside Geneva.
It was the culmination of a process launched last November in Tunis.
Mr Dbeibah called on regional and international countries to co-operate with Libya’s interim administration.
Eastern Libyan forces on Saturday evening welcomed the appointment of the interim government, with Libyan National Army leader Field Marshal Khalifa Haftar congratulating “the national figures” chosen.
“The Libyan people hope that it will work tirelessly to provide services and prepare the country for general elections on December 24, 2021,” Field Marshal Haftar said.
Losing candidates in the vote – including the speaker of the eastern-based parliament Aguila Saleh, the interior minister of the western-based government Fathi Bashagha and defence minister Saleh Namroush – have supported the new government.
The UAE, Egypt and Turkey all offered support to the process and welcomed the news.
Britain, France, Germany, Italy and the US welcomed the interim government, but cautioned of a "long road ahead" and said it would have to offer Libyans essential public services.
The delegates in Geneva also chose Mohamed Menfi, a Libyan diplomat from the country’s east, as chairman of the three-member Presidential Council.
Acting UN envoy to Libya Stephanie Williams, who co-ordinated the week-long talks in Switzerland, said the selection of the interim government was a "historic moment".
Libya descended into chaos after the 2011 uprising that removed and killed longtime dictator Muammar Qaddafi.
The country has been divided since 2015 between two governments, one in the east and one in the west.
In the centre of the capital Tripoli, citizens cautiously welcomed the news.
"At first, Libyans were not optimistic. But yesterday, the joy was palpable, because we saw these initiatives for the emergence of a state," Adil Al Kakli, 43, told AFP.
He said the plan to hold elections in December was too ambitious.
Louay Khouzam, 37, said she saw "hope for change", but still believed that polls would not happen before the end of the year.
The joint military committee set up to de-escalate the standoff between fighters from the two sides entrenched around the front lines near Sirte, said a collective force would begin demining operations on February 10.
Preparations are under way for the opening of the coastal road between the Cyrenaica region and Tripoli, a transit route between Libya’s east and west that has been closed since April 2019.
The committee agreed to reopen the road last November to let people move more freely and help to fulfil an October ceasefire agreement.
It also welcomed Libya’s new presidential council and unified government.
LNA military delegation head Gen Mraje Omami said the sides recently held meetings to see “what can be done in terms of achieving the comfort of the citizens and ending the fighting in Libya”.