The United Nations General Assembly, composed of 193 member states, has often been sympathetic to Palestinians. Its commemoration on Monday came at a tense period in Israel, Gaza and the occupied West Bank, where violence has surged this year. While Palestinians celebrated the U.N. action as validation, the Israelis saw it as an attack on their state.

Mr. Abbas called for the suspension of Israel’s membership from the United Nations, saying that the Jewish state never “fulfilled nor respected its obligations and commitments” as a prerequisite to its membership, and had violated resolutions.

Mr. Abbas received a standing ovation and two rounds of long applause after his speech, which lasted over an hour. Chants of “free Palestine” and “end the occupation now” were shouted from the audience.

Israel’s ambassador to the United Nations, Gilad Erdan, condemned the event as “shameful” and called for countries to boycott it in a letter he sent to diplomats on Sunday.

“Attending this despicable event means destroying any chance of peace by adopting the Palestinian narrative calling the establishment of the state of Israel a disaster,” Mr. Erdan said in a video statement.

The event was organized by the Committee on the Exercise of the Inalienable Rights of the Palestinian People, a body made up of 25 member states that was created in 1975 by a General Assembly mandate to promote the rights of Palestinians and support peace. Members include India, Turkey, South Africa, Venezuela and Malta.

Member states of the U.N. General Assembly voted in November to approve a resolution calling for the commemoration. It will continue on Monday evening with another event at the General Assembly hall with an “immersive experience” of the Nakba with live music, photographs, videos and testimonials.

“The Nakba and the suffering of generations of Palestinians is a story rarely taught in history books, too often eluded and forgotten,” said the chairman of the committee, Cheikh Niang, Senegal’s ambassador to the United Nations. “Today the resilience of Palestinians through history, but particularly since 1948, must be recognized.”

Around 700,000 Palestinians were expelled or fled their homes in 1947 and 1948 during the wars surrounding Israel’s establishment as a state. Most live as refugees in camps in neighboring nations, and their right to return home is a major issue in any two-state solution. Many of the villages they left behind were taken over by Israelis or destroyed.

The events are the subject of a long-running dispute. Palestinians see them as an act of ethnic cleansing instigated by Israeli militias, which killed hundreds of Palestinians in addition to driving thousands from their homes.

But to Israelis, the conflict was a war of survival against invading Arab armies and hostile local militants who committed atrocities and who rejected a U.N. plan to divide the land between Jews and Arabs.

For many Israelis, the Palestinian exodus was largely voluntary, encouraged by Arab leaders, and was accompanied by the persecution and expulsion of Jews from their homes in Palestine and elsewhere in the Middle East.

Violence in Gaza and the occupied West Bank has risen recently. On Saturday, Israel and the militant group Palestinian Islamic Jihad agreed to a cease-fire that ended five days of fighting that left 35 people dead.

The two-hour commemoration in a packed General Assembly hall began with a video by Shireen Abu Akleh, the Palestinian-American journalist from Al-Jazeera who was fatally shot by an Israeli soldier last May. The report showed scenes of Israeli violence against Palestinians. The New York Arabic Orchestra, directed by the four-time Grammy Award-winning musician Eugene Friesen, performed. And the master of ceremonies, Maher Nasser, a senior U.N. official and Palestinian refugee, said the goal of the event was to convey “a history of endurance, remembrance and holding on to beautiful traditions.”

The event did not appear to prompt a widespread reaction from Palestinians in Gaza, Israel, and the West Bank, but some Palestinian rights groups noted the significance of the U.N. commemoration.

The International Commission to Support Palestinians’ Rights, a rights group based in Gaza, called it “a unique and unprecedented step” and said that it should be “translated into enabling the Palestinian people to exercise their right to independence and return.”

Hani Akkad, a Palestinian political analyst, wrote in al-Quds newspaper that the event confirms “the justice of the Palestinian cause and the legality of the Palestinian national struggle,” and is a reminder that the world has not forgotten the Nakba “no matter how much the occupying state tried to portray itself as a victim.”

Separately from the U.N. event, thousands of Palestinians across Gaza, Israel and the West Bank held rallies and protests to commemorate the Nakba.

In Ramallah, in the West Bank, hundreds gathered outside the Yasir Arafat Mausoleum, where the former Palestinian president is buried. They waved Palestinian flags in a rally attended by Prime Minister Mohammad Shtayyeh.

At Tel Aviv University in Israel, dozens of students stood at the campus entrance and held Palestinian flags.