The position had been held for years by the late Saeb Erekat, who was also the PLO's chief negotiator in the now moribund peace talks with Israel.

Erekat died of coronavirus complications in 2020.

Sheikh, the Palestinian Authority's civil affairs minister, is seen as a possible successor to Abbas.

A veteran of Abbas' Fatah movement, he has cultivated ties with foreign diplomats and with Israel, including by meeting with Foreign Minister Yair Lapid.

Once the undisputed champion of the Palestinian cause, the PLO has lost much of its relevance since the establishment of the Palestinian Authority in 1994.

PLO chairman Abbas, who is also the PA president, is 87 years old and has seen support dive to historic lows in opinion polls, standing accused of autocracy in rare West Bank street protests last year.

Palestinians have not been to the ballot box for 16 years as Abbas scrapped elections scheduled for last year.