The US is to open its new embassy in Jerusalem - a move praised by Israel but condemned by Palestinians who are gathering for mass protests.
Top US officials will attend the event, including President Trump's daughter Ivanka and her husband, Jared Kushner.
Donald Trump's decision to move the embassy from Tel Aviv has angered Palestinians, who claim East Jerusalem as the capital of a future state.
Israel regards it as its "eternal and undivided" capital.
President Trump's decision last year to recognise it as Israel's capital broke with decades of US neutrality on the issue, and put it at odds with most of the international community.
A small interim embassy will start operating on Monday inside the existing US consulate building in Jerusalem.
A larger site will be found later when the rest of the embassy moves from Tel Aviv.
The opening ceremony was brought forward to coincide with the state of Israel's 70th anniversary.
President Trump is expected to address those attending Monday's event via video link.
Alongside Ivanka Trump and Jared Kushner, who are both senior White House advisers, Treasury Secretary Steven Mnuchin and Deputy Secretary of State John Sullivan will be at the ceremony.
The EU has voiced strong objections to the embassy move.
How did Israel and Palestinians react?
Israeli Prime Minister Benjamin Netanyahu called on "all countries to join the US in moving their embassies to Jerusalem".
Palestinian Authority President Mahmoud Abbas has described Mr Trump's decision as the "slap of the century".
Thousands of Palestinians are gathering for a protest along the perimeter fence that separates Israel and the Gaza Strip on Monday.
The timing of the embassy move has led to concerns about increased tension in Gaza.
Since the end of March, more than 40 Palestinians have been killed by Israeli soldiers in protests at the border.
UN human rights chief Zeid Ra'ad al-Hussein has accused Israel of using "excessive force".
Israel maintains it has acted legitimately to protect its civilians from militants trying to breach the border.
Why is the move so controversial?
The status of Jerusalem goes to the heart of the Israeli-Palestinian conflict.
Israeli sovereignty over Jerusalem is not recognised internationally and, according to the 1993 Israel-Palestinian peace accords, the final status of Jerusalem is meant to be discussed in the latter stages of peace talks.
Since 1967, Israel has built a dozen settlements, home to about 200,000 Jews, in East Jerusalem. These are considered illegal under international law, although Israel disputes this.
Various countries once had embassies based in Jerusalem - but many moved after a 1980 law saw the country explicitly claim the city's east, despite UN objections.
The day after Israel marks the anniversary of its statehood, Palestinians commemorate what they refer to as the Nakba or Catastrophe, when hundreds of thousands of their people fled their homes or were displaced following the foundation of the Israeli state in 1948.
