Kushner met with Israeli Prime Minister Benjamin Netanyahu as Israel celebrated Jerusalem Day, commemorating the 51st anniversary of when Israel gained control over the city after the 1967 Six Day War.
On Monday, the U.S. embassy will officially begin its move from Tel Aviv to Jerusalem, where it will be staffed by about 50 people including U.S. ambassador to Israel David Friedman's aides and U.S. consular officers already working at the site.
Much of the embassy staff will remain at the facility in Tel Aviv, which will be designated as a consular office, until 2019 when the U.S. State Department completes expansion of the embassy in Jerusalem.
About 800 people are expected to attend the opening on Monday and Trump will address the event via video message.
"President Trump promised to recognize Jerusalem as the capital of Israel and he did so. He promised to move the American Embassy to Israel and he is doing so. Of course we will all celebrate this day, a real celebration, tomorrow," Netanyahu said Sunday.
Last year, Trump said the United States would recognize the Jerusalem as the capital of Israel and pledged to move the U.S. embassy from Tel Aviv.
The decision was met with criticism from Palestinians and other countries, including some European nations which won't attend the celebration Monday.
Thousands of people gathered in two cities in Jakarta Friday to protest the move, with many carrying Palestinian flags and scarves in a show of solidarity.
A rally of 200 protesters also gathered in Jerusalem Saturday night to demonstrate against the embassy move.
Senior Palestinian official Ahmad Majdalani said Monday's embassy opening will be "a day of rage" as more protests are expected, including two planned outside the ceremony.
"We want to make sure that one event doesn't lead to another, meaning that if today things will be quiet in Jerusalem then of course hopefully tomorrow things will be quiet as well," Israeli police foreign spokesman Micky Rosenfeld said.