Amid international furor and bloody Palestinian clashes, the United States opened on Monday its controversial embassy to Israel in Jerusalem.
The opening was accompanied by violent Gaza border clashes that left at least 50 Palestinians dead and 2,000 injured from Israeli fire.
The clashes erupted before a White House delegation and Israeli officials opened the embassy at an inauguration ceremony in Jerusalem and continued throughout the day.
It was the bloodiest day in the Israeli-Palestinian conflict since a 2014 Gaza war.
Israeli fire claimed the lives of eight children under the age of 16, said the Palestinian envoy to the UN.
"We condemn in the strongest terms these atrocities by the Israeli occupying forces, using this massive fire power against civilians who have the right to demonstrate peacefully -- and they have been demonstrating peacefully," said Ambassador Riyad Mansour.
Tens of thousands had gathered near the border in protest while smaller numbers of stone-throwing Palestinians approached the fence and sought to break through, with Israeli snipers positioned on the other side.
The embassy inauguration nonetheless went on as planned, attended by a Washington delegation that included US President Donald Trump's daughter Ivanka and her husband Jared Kushner, both White House aides.
Ivanka Trump helped declare the new embassy open and a plaque and seal were unveiled before the 800 guests at the ceremony.
Trump addressed the ceremony by video.
"Our greatest hope is for peace," he said despite the Palestinian anger the move has provoked.
"The United States remains fully committed to facilitating a lasting peace agreement."
Israeli Prime Minister Benjamin Netanyahu told Trump in his address that "by recognizing history you have made history."
He added later: "We are in Jerusalem and we are here to stay."
He later defended the Israeli troops’ use of force, saying via Twitter: "Every country has the obligation to defend its borders.”
Along the Gaza border, crowds built throughout the day in the Palestinian enclave less than 100 kilometers (60 miles) away from Jerusalem and sealed off from Israel by a blockade.
EU foreign policy chief Federica Mogherini said "we expect all to act with utmost restraint to avoid further loss of life."
The inauguration follows Trump's deeply controversial December 6 recognition of the disputed city as Israel's capital. The ceremony took place at what until now had been a US consulate building in Jerusalem.
Saeb Erekat, Palestine Liberation Organization secretary-general, called it a "hostile act against international law".
Arab League chief Ahmed Abul Gheit blasted as "shameful" countries that were celebrating the embassy opening.
Beyond the disputed nature of Jerusalem, the date of the embassy move is also key.
May 14 marks the 70th anniversary of the founding of Israel.
The following day, Palestinians mark the "Nakba", or catastrophe, commemorating the more than 700,000 Palestinians who fled or were expelled from their homes in the 1948 war surrounding Israel's creation.
Palestinian protests are also planned for Tuesday.
There had already been weeks of protests and clashes along the Gaza border, with 97 Palestinians killed by Israeli fire there since March 30.
No Israelis have been wounded and the military has faced criticism over the use of live fire.
Palestinian President Mahmud Abbas condemned Israeli "massacres", declaring three days of mourning,
He said "the US is no longer a mediator in the Middle East," and the new embassy was tantamount to "a new American settler outpost" in Jerusalem.
The Hamas movement vowed protests would continue.
