White House adviser Jared Kushner is leading a delegation of Trump administration officials to the Middle East to discuss the possibility of resuming the Israeli-Palestinian peace process.
The White House said Mr Kushner left the US on Sunday for the Middle East with envoy for international negotiations Jason Greenblatt and deputy national security adviser Dina Powell.
They are expected to be in Israel on Wednesday and to meet Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas separately on Thursday.
The three are also expected to meet leaders from Saudi Arabia, the United Arab Emirates, Qatar, Jordan and Egypt during their trip.
Palestinians are hoping for some clear answers on key disputes with Israel from Mr Kushner.
They have shown increasing signs of impatience in recent days, saying that after more than six months in office, the US president has still not laid out a vision for peace in the region.
Ahmad Majdalani, a senior aide to Mr Abbas, said the Palestinians asked Mr Kushner for the US position on two key issues - Israeli settlements and support for Palestinian independence - during his last visit to the region in June.
"Since then we didn't hear from them," he said.
"We hope they bring clear answers this time. If not, then the peace process cannot be resumed because we cannot negotiate from scratch."
The Palestinians are seeking a freeze in Israeli settlement construction and a US endorsement of Palestinian independence as part of a two-state solution with Israel.
The Palestinians say that continued Israeli construction in the West Bank and east Jerusalem - captured territories sought by the Palestinians for their state - undermines their dream of independence.
Mr Kushner, the president's son-in-law, is expected to meet Israeli and Palestinian officials on Thursday as he tries to restart talks. The last round broke down over three years ago.
Mr Trump has cast the elusive pursuit of peace between Israelis and Palestinians as the "ultimate deal", but he has given few indications of how he plans to reach it.
With his administration still coping with the fallout from his handling of the deadly violence in Charlottesville, Virginia, and Mr Netanyahu facing a growing police investigation into possible bribery and corruption, the odds of any major breakthroughs on this trip seem low.
Mr Trump has not explicitly endorsed the two-state solution, the cornerstone of US policy for nearly two decades and the international community's preferred outcome.
He has urged Israel to show restraint in settlement construction, but not demanded a freeze, disappointing the Palestinians.
He also has backed away from a campaign pledge to move the US Embassy from Tel Aviv to Jerusalem. Israel had welcomed the promise, while the Palestinians strongly opposed it.
Israel claims east Jerusalem, home to sensitive religious sites, as part of its capital. The Palestinians want the area, captured by Israel in 1967, as the capital of their future state.