The exiled political leader of Hamas, Khaled Meshaal, is due to make his first ever visit to Gaza to mark the organisation’s 25th anniversary.
Mr Meshaal has not set foot in the Palestinian territories since leaving the West Bank in 1967 and is scheduled to address a mass rally on Saturday.
His visit follows a ceasefire that ended days of violence between Hamas-run Gaza and Israel last month.
The Islamist militant group has governed Gaza since 2007.
‘Made in Gaza’
Mr Meshaal is due to enter Gaza from Egypt. Officials at the Rafah border crossing said his wife had arrived late on Thursday.
Mr Meshaal is expected to visit the home of late Hamas founder Sheikh Ahmed Yassin, as well as that of Ahmed Jabari, the military commander killed in an Israeli strike last month.
Jabari’s death marked the start of an eight-day conflict that left about 170 Palestinians and six Israelis dead.
Hamas spokesman Sami Abu Zuhri said in a statement that Mr Meshaal’s visit was “a fruit of the victory of the resistance over the occupation”.
A huge rally on Saturday is expected to be the centrepiece of his three-day tour.
BBC Middle East correspondent Yolande Knell says Mr Meshaal is scheduled to address the rally in Gaza City and will talk about the organisation’s future strategy towards Israel.
Correspondents say Israel – which along with the US and EU considers Hamas a terrorist organisation – appears to be turning a blind eye to the visit.
Israeli foreign ministry spokesman Yigal Palmor said that Israel had no say over who entered Gaza from Egypt.
“We have no position on different individuals within Hamas,” he said, according to AP news agency. “Hamas is Hamas is Hamas.”
On Thursday, Palestinian workers were setting up a stage for Saturday’s rally that included a replica of a type of rocket Hamas has fired into Israel. “Made in Gaza,” was written on it.
Mr Meshaal was born in the West Bank in 1956. He moved to Kuwait after the 1967 Middle East war and later Jordan, where his involvement with Hamas began.W
Mr Meshaal survived an Israeli assassination attempt in Jordan in 1997 and was briefly jailed there, before being expelled and travelling to Qatar.
He became Hamas’s political leader in exile in 2004 when Sheikh Yassin was assassinated by Israel.
Mr Meshaal ran operations from Damascus until February this year, when the unrest there prompted another move. He now bases himself in Qatar and Egypt.
Hamas was created in 1987 after the beginning of the first intifada – or Palestinian uprising – against Israel’s occupation of the West Bank and Gaza.
Under its charter, Hamas is committed to the destruction of Israel.
Last week, Israel announced it would move ahead with building thousands of new homes in Israeli settlements in the West Bank and East Jerusalem.
The move came after the UN General Assembly voted to recognise the Palestinians as a non-member observer state.