Trump addressed the ceremony by video.
"We curse the massacre carried out by Israeli security forces, encouraged by this step, on the Palestinians participating in peaceful demonstrations", its statement said.
Mansour spoke just hours after the ceremony to inaugurate the relocated us embassy concluded.
"Of all the things President Trump could have done, doing this (embassy move) is the strongest signal he could send to the Israeli people", South Carolina's Graham said.
Dozens of Palestinian protesters had already been killed by Israeli army fire in the weeks before the violence on Monday, with the marches having begun in late March 2018.
The military also said one of its fighter jets had struck five targets at a Hamas training facility in Gaza. 'The Hamas terrorist organisation declares it intends to destroy Israel and sends thousands to breach the border fence in order to achieve this goal'. Human Rights Watch denounced a "bloodbath".
Besides, "it will intensify anti-Zionist and anti-US moves in the region and across the world", it said. 'Every country has an obligation to defend its borders, ' he said. The resolution didn't name the US explicitly but expressed "deep regret" at any decision to recognise Jerusalem as Israel's capital - which US President Trump chose to do on December 6, 2017.
The clashes have raised doubts about Mr Trump's ambitions to broker what he once said would be the Middle East "deal of the century".
Hamas and other jihadist groups have "a national and religious issue around which to rally: defense of Jerusalem", Mr. Miller said. "I don't see any resolution, unfortunately", said Petras, a retired professor at Binghamton University in NY.
Meanwhile, the United Nations body monitoring implementation of the convention on eliminating racial discrimination has urged Israel, which is a State party, to immediately end the disproportionate use of force against Palestinian demonstrators in the Gaza Strip, refrain from any act that could lead to further casualties and ensure prompt and unimpeded access to medical treatment for those injured. Many Palestinians have taken offense to the U.S. moving its embassy on the anniversary of Nakba, which they see as adding insult to injury. For Palestinians, Tuesday marks the anniversary of "naqba", or catastrophe, when hundreds of thousands of people fled or were forced from their homes during the war surrounding Israel's founding.
Protests are expected to resume today.
"We are here today to call on our elected officials to condemn Israel's attacks on Gaza", protester Tali Ruskin said.
"So there's no responsibility beyond that on the Israeli authorities, kill at will?"