Analysts say the shift pushes Hamas deeper into the fold of the Iran-led "axis of resistance" against Israel that includes Syria as well as Lebanon's Hezbollah movement and Yemen's Houthi militias.

Hamas' move comes amid fundamental changes in Middle East relationships that saw the movement's long-time ally Türkiye restore full diplomatic ties in August with Israel, the Gaza group's arch-enemy.

A delegation led by Hamas officials is expected in the Syrian capital next week, following a series of preparatory meetings.

Hamas sees itself as leading the armed resistance against Israel and its blockade of Gaza, but it is considered a terrorist group by Israel, the United States and the European Union.

The group last month hailed its newly warming ties with the Syrian regime of Bashar al-Assad as "a service to the (Palestinian) nation" whose people also live under Israeli occupation in the West Bank.

Hamas cited the "rapid regional and international developments surrounding our cause and our nation" -- without directly referring to Israel's restored ties with Türkiye and relations with several Arab nations.

The shift comes as Syria's ally Iran, now hit by a wave of protests, is sharply at odds with Western and some regional powers, especially over its nuclear program, which Israel sees as an existential threat.

‘Resistance axis’

The leadership of Hamas, which has ruled the poverty-stricken enclave of Gaza since 2007, has long been based abroad as Israel's military has repeatedly struck militant targets in the territory.

Hamas had its headquarters in Damascus but closed them in 2012 after the group, which emerged from the Muslim Brotherhood movement, sided with the opposition against Assad.

Its leaders then moved to the Gulf state of Qatar and to Türkiye, which had cut ties with Israel over a deadly Israeli commando raid on a Turkish aid ship that had tried to breach the Gaza sea blockade.

The Hamas delegation expected in Damascus next week is to be headed by Khalil al-Hayya, its head of Arab relations, said Khaled Abdel Majid, head of the Palestinian Popular Struggle Front, a group close to the Syrian regime.

Hamas' decision to ally again with Damascus follows numerous visits by its officials to Syria, both "secret and public", a senior Hamas source told AFP on condition of anonymity.

Those meetings were mediated by Iran and Hezbollah, which have both fought on Assad's side in the war, the source said.

All this reflects Iran's wish to bolster the "axis of resistance" which also includes Palestinian group Islamic Jihad, said Mukhaimer Abu Saada, a political science professor at Gaza's Al-Azhar University.

As Iran's talks to restore its frayed 2015 nuclear deal with major powers have faltered, it has turned closer to Russia, which is also facing deepening international isolation over its war in Ukraine.

Hamas chief Ismail Haniyeh, based in Qatar, last month travelled to Moscow and met Russia's Foreign Minister Sergei Lavrov.

As the group returns to Syria, the senior Hamas source told AFP, it plans to "open a representative office in Damascus soon, as a first step towards the return of normal relations".

The former political chief of Hamas, Khaled Meshaal, once enjoyed rare privileges in Damascus and had a personal relationship with Assad.

Wary Hamas

However, it remains unlikely the Syrian regime will allow Hamas to rebuild a foothold that has "the weight it had a decade ago", said Jamal al-Fadi, also a politics professor at Al-Azhar.

The Hamas leadership may also be wary of spending too much time in Syria, given that Israel regularly launches air strikes on the country, mainly targeting pro-Iranian fighters.

"Hamas' relationship with Syria at the moment will be subject to difficult security considerations," said Fadi. "It exposes its leaders and its activists to the dangers of being easily targeted by Israel."

The budding Hamas-Syrian ties have exposed rifts within the movement.

Saleh al-Naami, a politics professor at the Islamic University of Gaza who is close to Hamas, described the deal with Damascus as a "moral sin".

"It also does not reflect the base of the movement and of the vast majority of its (political) elite," he wrote on Twitter.

However, the head of Hamas' political committee, Bassem Naim, said the decision followed years of regional and international discussions.

"In the end, Hamas went with the majority opinion on the resumption of the relationship with Syria," said Naim. "There is no choice but for Hamas to be at the center of the resistance axis."