Speaking from the Rose Garden during an event dedicated to religious liberties, Mr Trump said he would use the trip – his first foreign foray since becoming president – to build cooperation between Muslims, Christians and Jews for fighting terrorism.
“Our task is not to dictate to others how to live,” Mr Trump said. “But to build a coalition of friends and partners who share the goal of fighting terrorism and bringing safety, opportunity and stability to the war-ravaged Middle East.”
Mr Trump has made fighting Isil and forging peace in the Middle East a focus of his foreign policy.
The White House has been criticised by rights groups for its decision to define extremism as a problem born from Islam, and subsequent attempts to temporarily ban travel to the US from several-Muslim majority countries.
Mr Trump’s first stop will be Saudi Arabia, where the president said he will take part in a “truly historic gathering” that will include “leaders from across the Muslim world”.
“We will begin to construct a new foundation of cooperation and support with our Muslim allies to combat extremism, terrorism and violence,” Mr Trump said.
Barack Obama, Mr Trump’s predecessor, had a testy relationship with Saudi Arabia, which vehemently opposed his rapprochement with Iran.
Mohammed bin Salman, Saudi Arabia’s powerful Deputy Crown Prince, met Mr Trump in Washington in March in a visit a senior Saudi adviser called a “historical turning point” in relations.
Mr Trump complained in an interview last week that Washington was losing a “tremendous amount of money” in defending the Kingdom, a key strategic partner in the Middle East.
But he has said he is counting on Gulf allies to spearhead the ideological battle against Isil, as well as participate in military efforts.
Mr Trump, who met with Israeli Prime Minister Benjamin Netanyahu at the White House in February, will then head to Israel.
In meeting with Palestinian President Mahmoud Abbas at the White House earlier this week, Mr Trump vowed to help put an end to the near 70-year-long conflict.
A senior White House official said there was a “catastrophe” unfolding in the Middle East, and that Mr Trump would use this trip to stress that Israel is not the cause of the problem.
“People blame Israel,” he said. But he added that it is now “painfully obvious to everyone” that the violence today has been brought about by “Salafist jihadists” and “also by Iran”.
Mr Trump will then head to Italy, where he is expected to meet with Pope Francis at the Vatican.
The trip will end with a day-long meeting with Nato leaders in advance of a long-planned summit in Istanbul next year.