Pope Francis brought together the presidents of Israel and the Palestinian Authority on Sunday at the Vatican to join in prayer and promise to seek peace — though their governments are officially not talking.

Israeli President Shimon Peres and Palestinian leader Mahmoud Abbas concluded the two-hour ceremony by kissing each other on the cheek and then planting an olive tree, gestures intended to signal a commitment to trying to end one of the longest-running, most intractable conflicts in the world.

“Peacemaking calls for courage, much more so than warfare,” Pope Francis said during the gathering, dubbed a prayer summit. “Instill in our hearts the courage to take concrete steps to achieve peace.”

The meeting was historic — and may not lead to much. U.S.-brokered peace talks collapsed in April amid bitter recriminations by both sides.

Still, the prayer summit was a remarkable show of the new pope’s intention to mix spiritual matters and real-world diplomacy. Francis was visiting the Holy Land just two weeks ago when he invited the two leaders to come to the Vatican.

“No one is presumptuous enough to think peace will break out on Monday,” the Rev. Pierbattista Pizzaballa, a church official in charge of Catholic sites in the Holy Land, told Reuters.

“The intention of this initiative is to reopen a road that has been closed for some time; to re-create a desire, a possibility; to make people dream,” he said.

As the sun cast long shadows from hedges in the Vatican gardens, an ensemble played Samuel Barber’s stirring “Adagio for Strings.”

During the service, Jewish, Christian and Muslim prayers were recited in English, Italian, Arabic and Hebrew. The words were intended to thank God for His creation, to seek forgiveness for the failure to act as brothers and sisters, and to ask for peace in the Holy Land.

Peres, who is 90 and nearing the end of his seven-year term as Israeli president, said: “I was young, and now I am old. I experienced war, I tasted peace. Never will I forget the bereaved families — parents and children — who paid the cost of war. And all my life I shall never stop to act for peace, for the generations to come. Let us all join hands and make it happen.”

A new government

The prayer ceremony came at a time when relations between Jerusalem and Ramallah are in dismal shape. Israel has also found itself at odds with the Obama administration over the Israeli government’s announcement last week that it would build more homes in Jewish settlements in the West Bank as a way to punish a new Palestinian government backed by militant Islamists.

Last week, rival Palestinian political factions overcame seven years of acrimony to form a new “government of national unity,” supported by the Islamist militant group Hamas, which the United States and Israel have branded a terrorist organization.

The Obama administration worked behind the scenes to make sure the new transitional government, composed of technocrats, would not trigger U.S. prohibitions on aid to a Palestinian government that has “undue” Hamas presence. U.S. diplomats reason that it is better to maintain their influence over Palestinian leaders than to walk away.

Israel says it will not work with a government backed by Hamas. On Sunday, Prime Minister Benjamin Netanyahu said Hamas would not become more moderate, as some may hope, and he called on the international community to press Abbas to disband the government.

The United States said it would watch carefully to see whether the new government abides by its promises to continue to renounce violence and uphold previous commitments, including its recognition of Israel.

Three days after the new Palestinian ministers were sworn in, Israel’s housing minister, Uri Ariel, announced plans to build 1,500 housing units in the West Bank and East Jerusalem, on lands Palestinians claim for a future state and its capital.

Ariel called it a “fitting Zionist response” to the formation of what he called the “Palestinian terrorist government.”

Hanan Ashrawi, a leader of the Palestine Liberation Organization, said that the continued settlement construction is “a systematic policy that aims to rob the Palestinians of their land and ethnically cleanse them from historical Palestine.”

Criticism from the U.S.

The announcement of another round of settlement construction has been criticized by U.S. officials and the European Union.

“We oppose settlement construction in the West Bank as well as announcements regarding such construction,” the U.S. ambassador to Israel, Dan Shapiro, told Army Radio on Thursday. “We would do so with or without this disputed case of a new Palestinian transitional government.”

Israeli Finance Minster Yair Lapid, who favors returning to negotiations with the Palestinians, said Sunday that American-Israeli relations have reached “an unprecedented crisis.”

On Sunday, U.N. Middle East envoy Robert Serry was the first top diplomat to meet with unity government members in the Gaza Strip. According to a report from the Associated Press in Gaza, Serry called for lifting the blockade of goods and the restrictions on travel to the strip enforced by Israel and Egypt.

Serry also said the United Nations would now supply more aid to Gaza, not less. The Gaza Strip has been controlled by Hamas and its military wing since 2007 and has served as the launch pad for thousands of rocket attacks against Israel.