Israeli President Shimon Peres and Palestinian leader Mahmoud Abbas called for peace on Sunday at an unprecedented prayer with Pope Francis on Sunday amid heightened tensions between the two sides.

Peres said peacemaking was a "duty" and a "holy mission" at the spiritual event in the Vatican Gardens, and Abbas called for a "comprehensive and just peace" that could bring stability to the Middle East.

A Palestinian fisherman in the Gaza Strip died on Sunday from Israeli gunshot wounds sustained last month, an official in the outgoing Hamas-run health ministry said.

"Fisherman Imad Shukri Salem, 52, died this morning from wounds he sustained two weeks ago," spokesman Ashraf al-Qudra told AFP, saying troops on a naval vessel fired at him while he was fishing.

Pope Francis on Sunday hosts an unprecedented peace prayer meeting with Israeli President Shimon Peres and Palestinian President Mahmud Abbas in a symbolic gesture to foster dialogue but unlikely to have any immediate effect.

Tensions are running high between the two sides following the formation of a new Palestinian unity government backed by the Islamist group Hamas and the announcement of Israeli plans for building 3,200 new settler homes.

U.N. chief Ban Ki-moon expressed concern Friday about the deteriorating health of Palestinian prisoners on hunger strike, calling on Israel to charge or release them without delay.

Around 125 Palestinian prisoners have been on hunger strike for more than six weeks, most of them administrative detainees protesting against being held indefinitely without trial.

The European Union said Thursday it was "deeply disappointed" after Israel unveiled plans to build another 3,200 settler homes, and called for the decision to be reversed, as the U.N. urged Israel to respect “international law.”

Tenders for nearly 1,500 new settlement houses and plans to advance some 1,800 others were issued in retaliation for the formation of a Palestinian unity government backed by Hamas and the international community.

The Israeli government on Thursday ordered officials to move forward with plans for another 1,800 settler homes, just hours after issuing tenders for 1,500 housing units, an official said.

"The political echelon has ordered the Civil Administration to advance 1,800 new (housing) units," the Israeli official told Agence France Presse on condition of anonymity, referring to a defense ministry unit responsible for all West Bank planning issues.

U.S. Secretary of State John Kerry on Wednesday dismissed a presidential election in war-ravaged Syria as "a great big zero" as he visited neighboring Lebanon.

Tuesday's "elections are non-elections, the elections are a great big zero," Kerry told reporters in Beirut after arriving on an unannounced visit.

Palestinian prime minister Rami Hamdallah called Wednesday for international pressure on Israel to let Palestinians in annexed east Jerusalem vote in an upcoming general election.

Hamdallah's new unity government is tasked with organizing parliamentary and presidential elections in the Gaza Strip and West Bank by the end of the year.

The European Union on Tuesday welcomed the new Palestinian unity government as "an important step" in Palestinian reconciliation.

An EU statement hailing its appointment however said future support would depend on the government sticking to principles such as the need for a two-state solution and Israel's right to exist.

Israeli security forces killed a Palestinian man after he shot and wounded a border guard in the northern West Bank late Monday, the army said.

"An armed Palestinian opened fire at the Tapuach junction and wounded an Israeli border guard," said an army spokeswoman. "Soldiers and border guards returned fire and killed the assailant."