Former Libyan prime minister Mahmoud Jibril died in Egypt on Sunday after contracting the coronavirus.
Jibril served as the country's interim premier for more than seven months, from March to October 2011, during the Libyan civil war.
Khaled Al Mrimi, secretary of the Alliance of National Forces party that was founded by Jibril in 2012, said he died in Cairo after two weeks in hospital.
Coronavirus around the Middle East
In a tweet on Sunday, UAE Minister of State for Foreign Affairs Dr Anwar Gargash expressed his condolences.
"We lost today a good friend, Dr Mahmoud Jibril, the ex-Libyan prime minister who passed away in Cairo," Dr Gargash said.
"The deceased loyally worked for his country and people. True condolences and comfort to the family of the deceased."
Jibril, 68, was appointed head of the National Transitional Council during the civil war in which Libya's former leader Muammar Qaddafi was captured and killed.
Prior to this, he served as head of the National Economic Development Board for the Qaddafi regime before defecting to the rebel National Transitional Council at the start of the revolution in early 2011.
In October 2011, he announced that he would resign from government as soon as the country had been "liberated".
It was a promise he kept, stepping down from his post three days after the city of Sirte was captured and Qaddafi was killed.
In March 2012, he became the leader of the newly founded National Forces Alliance, which is now one of the largest political parties in Libya.
Supporters regarded Jibril as someone who could unify Libya's warring factions.
The alliance is composed of 58 political organisations, 236 charities and more than 280 independents.
It calls for moderate Islamic, democratic, civil state" that respects minority groups.
Libya announced its first official cases of the coronavirus last week, with only a handful of infections reported so far.