Saeb Erekat, a prominent Palestinian spokesman for decades, has died after contracting COVID-19, his family says.
Palestinian President Mahmoud Abbas on Tuesday declared a three-day mourning period for Erekat.
"The departure of the brother and the friend, the great fighter Saeb Erekat, represents a big loss for Palestine and for our people," Abbas' office in Ramallah in the occupied West Bank said in a statement.
"We feel deep sorrow for losing him, especially at such difficult times the Palestinian cause is living through."
Erekat, 65, the secretary general of the Palestine Liberation Organisation (PLO), confirmed on October 8 that he had contracted the coronavirus. Three years earlier he had undergone a lung transplant in the United States that left his immune system compromised.
Erekat's family said he "transitioned peacefully" in hospital on Tuesday. "Saeb lived a life full of thought, love, forgiveness and peace and he will be dearly missed," they said in a statement.
"Saeb has shown an extraordinary patience and resilience, with the same determination that has characterised his career to achieve freedom for Palestine and a just and lasting peace in our region.
Erekat, 65, was one of the most passionate and experienced advocates of the Palestinian cause.
Although well known in foreign ministries across the world and regularly featured in the media, he was on the second tier of Palestinian politics and diplomacy.
Fluent in English as well as his native Arabic, he was a high-profile spokesman for Palestinian leaders such as Yasser Arafat and Mahmoud Abbas, while never a serious candidate to succeed them.
He died after being hospitalised for weeks in Jerusalem's Hadassah Medical Centre.