Mr Trump has been criticised for handing his ally, Israeli Prime Minister Benjamin Netanyahu, a political victory without insisting on any Israeli concessions that might mollify Palestinians and help revive the moribund peace process.
Tension has grown across the Palestinian territories since December 6, when U.S. President Donald Trump officially recognized Jerusalem as the capital of Israel.
Tens of thousands of Palestinians are expected to gather along the border between Gaza and Israel Monday to protest as the US opens its embassy. "Who is Trump to come and say Jerusalem is Israel?"
Both the embassy move and the protests have symbolic timing. "We will pray for the boundless potential of the future of the US-Israel alliance, and we will pray for peace".
About two-thirds of Gaza's two million people are descendants of Palestinian refugees.
Israel has warned that it will prevent any border breach.
Since border rallies began on March 30, at least 48 Palestinians have been martyred - and hundreds more injured - by cross-border Israeli army gunfire, according to the Health Ministry. Marchers have thrown stones and burned tires at the fence and flown flaming kites over it to try to set Israeli fields on fire.
"The crossing will remain closed until the damages caused by the riots are repaired and will reopen in accordance with a situation assessment", an Israel Defense Forces spokesman announced on social media Saturday. Conricus said the tunnel took months to build and that the military had been tracking its construction for a number of weeks.
Observers say there is concern that expanding Palestinian protests may lead to clashes with Israeli forces. Since the end of March, weekly protests haven taken place there every Friday.
"For 70 years Jerusalem been awaiting global recognition, until President Donald Trump, in a courageous move, recognized Jerusalem as the eternal capital of Israel", the Beitar Trump Jerusalem football club - formerly known as the Beitar Jerusalem Football Club - said on its Facebook page.
"Ashrawi said on the eve of the 70th anniversary of the Palestinian Nakba ("catastrophe"), a grave historical injustice that continues today, the United States will officially relocate its embassy from Tel Aviv to occupied Jerusalem, reneging on longstanding American commitments and policies and violating the most basic requisites of justice and legality".