A visit by Gaza's Hamas leader has angered the official Palestinian representatives in Tunisia who say they were ignored during the talks with the new government, a Palestinian source said Saturday.

Ismail Haniya, prime minister in the Hamas-ruled Gaza Strip, visited Tunis Thursday to meet with the new moderate Islamist-led administration while he was on a tour of the region.

The Damascus-based chief of Hamas was instrumental in getting Syria to accept an Arab observer mission into the country, the head of the Arab League said on Friday.

Nabil al-Arabi was speaking in Cairo after talks with Khaled Meshaal, the exiled head of the Palestinian Islamist group Hamas.

Gaza's Hamas premier Ismail Haniya held talks with Sudanese President Omar al-Bashir Thursday on his first official regional tour since the Islamists' 2007 power seizure in the Palestinian enclave.

Haniya, who arrived in Khartoum on Tuesday, was joined in the meeting by other high-ranking Hamas leaders -- the first time they had met as a group with Bashir, whose country has close ties with Hamas.

Representatives of all the Palestinian factions began meeting in Cairo on Tuesday to discuss ways of implementing a stalled reconciliation deal, delegates said.

But officials played down expectations of a breakthrough, with Fatah delegation head Azzam al-Ahmed telling Agence France Presse he did not expect any agreement on the key issues of security and an interim government "before the end of January."

Israel warned on Saturday that it would cut the supply of water and electricity to the Gaza Strip if rival Palestinian movements Fatah and Hamas form a unity government.

"The foreign ministry is examining the possibility of Israel pulling out of the Gaza Strip in terms of infrastructure," Deputy Foreign Minister Danny Ayalon told the daily Yediot Aharonot website.

Hamas is looking to focus its energies on popular resistance without giving up its right to wage armed struggle against Israel, the Islamist movement's leader Khaled Meshaal told Agence France Presse in an interview.

"Every people has the right to fight against occupation in every way, with weapons or otherwise. But at the moment, we want to cooperate with the popular resistance," the group's Damascus-based leader said in the interview late on Thursday.

Palestinian leader Mahmoud Abbas and Hamas chief Khaled Meshaal on Thursday hailed a new era of partnership between their two rival movements at talks in Cairo aimed at cementing a stalled a unity deal.

Speaking to reporters after several hours of talks, the two leaders said they had managed to iron out their differences and turn over a new page in their strained relationship.

Palestinian leader Mahmoud Abbas and Hamas chief Khaled Meshaal will meet in Cairo this week despite the unrest rocking Egypt, a senior Hamas official said on Tuesday.

The meeting between the exiled Hamas leader and Abbas, who heads the rival Fatah movement, will go ahead "as scheduled on Thursday," Hamas official Ismail Radwan told AFP.

Palestinian leader Mahmoud Abbas pledged on Wednesday to "speed up" work with Hamas to form a new caretaker government and to prepare for fresh elections.

In an address to the Palestinian leadership timed to mark seven years since the death of veteran leader Yasser Arafat and the 23rd anniversary of their declaration of independence, Abbas vowed to push ahead with efforts to cement a landmark unity deal between Fatah and Hamas.

Turkey on Wednesday welcomed a deal between Israel and Hamas in which a Franco-Israeli soldier, held for five years, is to be exchanged for more than a thousand Palestinian prisoners.

"We are happy," Turkish Foreign Minister Ahmet Davutoglu said, of the deal that will see the Palestinian militant group free Gilad Shalit, who they have held since 2006.