President Donald Trump on Monday will embark on a four-day tour of the Middle East, stopping in Saudi Arabia, Qatar and the United Arab Emirates on a trip underscoring the deepening economic ties between the United States and the Gulf kingdoms.

Traveling to a region facing ongoing diplomatic, political and security challenges — including Iran’s nuclear program, the humanitarian crisis in Gaza and war between Israel and Hamas, and the fate of Syria following a brutal 14-year civil war — Trump is expected to focus on business development and trade agreements on his trip, following commitments from Saudi Arabia and the United Arab Emirates to invest hundreds of billions of dollars in the United States and on joint investments over the next several years.

On Friday, White House press secretary Karoline Leavitt said Trump’s trip will “focus on strengthening ties” between the U.S. and the Gulf nations.

“President Trump will return to reemphasize his continued vision for a proud, prosperous and successful Middle East where the United States and Middle Eastern nations are in cooperative relationship and where extremism is defeated in place of commerce and cultural exchanges,” she said.

Saudi Crown Prince Mohammed bin Salman pledged to invest $600 billion in the United States over four years after Trump’s November victory, and the United Arab Emirates have also committed to a $1.4 trillion U.S. investment package over the next decade. Business and technology leaders will be convening in Riyadh around Trump’s trip for a Saudi-U.S. investment forum.

ABC News has also reported that the Trump administration is preparing to accept a luxury Boeing jumbo jet from the Qatari royal family for use as a presidential aircraft before being transferred to the Trump presidential library foundation after his term ends.

White House press secretary Karoline Leavitt responded to ABC News’ reporting, saying in a statement that “any gift given by a foreign government is always accepted in full compliance with all applicable laws.”

The president’s family has also traveled to the region and has expanded its business interests in the Middle East: The Trump Organization has partnered with developers on new projects in Saudi Arabia, Doha and the United Arab Emirates, and is involved in a cryptocurrency venture connected to a fund with ties to the Emirati government.

Leavitt on Friday dismissed questions about the president’s family’s business dealings in the region ahead of his trip and said Trump “has actually lost money for being president of the United States.”

“The president acts with only the interests of the American public in mind, putting our country first and doing what’s best for our country — full stop,” she said.

“It’s frankly ridiculous that anyone in this room would even suggest that President Trump is doing anything for his own benefit. He left a life of luxury and a life of running a very successful real estate empire for public service,” she later added.

Trump also began his first term in office with a visit to Saudi Arabia, in a break with his predecessors who had visited traditional U.S. allies and major trade partners on their first official foreign trips.

That trip to Saudi Arabia — which also included stops in Israel and later in Europe — focused on encouraging local partners to redouble efforts to fight “extremism” and terrorist groups, and work to marginalize Iran.

Since then, Saudi Arabia and other Gulf states have improved relations with Iran, and are now supportive of the Trump administration’s diplomatic efforts to address Iran’s nuclear program.

“Both the Saudis and the Emiratis have decided that their priority is economic investment and getting away from energy, and that war with Iran is like a big danger to all of that. So they’ve completely shifted on Iran,” Ilan Goldenberg, a Middle East specialist who worked in the Obama and Biden administrations, told ABC News.

The ongoing war between Israel and Hamas and the humanitarian crisis in Gaza also looms over Trump’s trip, given Israel’s plans to expand military operations in Gaza.

In Riyadh, Trump is expected to join a Gulf Cooperation Council meeting before he travels to Qatar.

While the president has aimed to ink a regional diplomatic agreement expanding on the Abraham Accords of his first term, the war in Gaza has effectively frozen efforts to normalize diplomatic relations between Israel and Saudi Arabia and other Arab countries, experts told ABC News.

“From the Saudi perspective, it makes it harder” to improve diplomatic relations with Israel, Zineb Riboua, a fellow with Hudson Institute’s Center for Peace and Security in the Middle East. “Because of what has happened and what is currently happening [in Gaza], they are struggling.”

Trump could hear from Arab leaders about the humanitarian situation in Gaza, given the U.S.’s ongoing military support for Israel, and Israeli plans to expand its campaign in Gaza to root out Hamas.

In February, Trump proposed that the U.S. “take over” Gaza and help rebuild it, a plan that was rejected by Arab leaders, who put forward their own counterproposal that the U.S. and Israel have opposed.

There have also been disputes between the U.S., Israel and Arab nations over how to administer humanitarian aid blockaded by Israel to Palestinians in Gaza.

Though the trip is Trump’s first planned foreign trip, he traveled to Rome and the Vatican in April to attend the funeral of Pope Francis.

On the sidelines of that trip, Trump met with Ukrainian President Volodymyr Zelenskyy as the two countries worked to cement a minerals deal.

Saudi Arabia has hosted bilateral peace negotiations between Russia and Ukraine, underscoring the kingdom’s growing political influence, in addition to its economic and commercial importance in the region.

Trump “sees the Gulf as they see themselves, as a real fulcrum of global power,” Jon Alterman, the Middle East Program Chair at Center for Strategic and International Studies, told ABC News.

“A lot of people in the world think the Gulf is an outlier. A bunch of small, wealthy states that rely on the United States for security, protection. The Gulf sees itself differently, and the president is suggesting he sees the Gulf differently,” Alterman said.

Trump could receive a lavish welcome from the Gulf monarchs in the region, similar to the royal treatment he received when he visited Saudi Arabia in 2017.

The Saudis rolled out the red carpet for his arrival, greeting him at the airport with a military jet flyover and later awarding him a gold medal — the nation’s top civilian honor — and treating him to a traditional sword dance.

Trump’s trip also comes on the heels of Hamas announcing that they will be releasing Israeli soldier Edan Alexander, a dual US citizen, which will be part of steps taken to achieve a ceasefire. Hamas said that they have been in contact with American officials over the last few days over the efforts to try and achieve a ceasefire deal.

President Donald Trump posted on his social media platform, Truth Social, Sunday evening, confirming that Alexander will be released from Hamas. Trump did not specify when Alexander was expected to be released, but said, “This is the first of those final steps necessary to end this brutal conflict.”