Amid much anticipation, Trump begins his first foreign trip in Saudi Arabia on Saturday

In this photo from March 14, 2017, US president Donald Trump shakes hands with Saudi defense minister and Deputy Crown Prince Mohammed bin Salman, in the state dining room of the White House in WashinShow more

ABU DHABI // Donald Trump will begin his first overseas trip in Riyadh on Saturday, where the US president and Saudi leaders hope to seal a major deepening of the strategic security and economic partnership that has been at the core of the two countries’ relationship for eight decades.

The US president’s visit to the home of Islam’s two holiest sites is also being billed by Riyadh and Washington as a resetting of ties with the Muslim world. Mr Trump will meet leaders of the GCC and have lunch with more than 50 heads of state, most of whom are from countries that are part of the Saudi-led Islamic Military Alliance.

The Saudi foreign minister, Adel Al Jubeir, said a number of agreements would be signed during the first part of the visit on Saturday when Mr Trump meets with King Salman and the royal court.

Riyadh and Washington were discussing several “initiatives” related to arms sales, economic and security cooperation and tackling terrorism, Mr Al Jubeir said.

He added that the visit would “bolster the strategic partnership between the two countries”.

Saudi officials have spared no effort to elevate the atmosphere around the visit beyond that of a typical US presidential trip. His wife, Melania, will dine with members of the royal family, while Mr Trump will engage with young Saudis on Twitter, their favourite medium. There will even be a concert intended as a symbol of the two countries’ partnership – country star Toby Keith and Saudi oud virtuoso Rabeh Sager will play together for an all-male audience in Riyadh on Saturday.

Intensive negotiations led by 31-year-old deputy crown prince Mohammed bin Salman and Mr Trump’s 36-year-old son-in-law and adviser, Jared Kushner, have been ongoing over a massive new arms sale to Riyadh worth up to US$300 billion (Dh1.1 trillion) over the decade.

Saudi Arabia, for its part, is set to roll out an economic partnership plan with Washington and US businesses that could include up to $40bn in infrastructure and tens of billions more in other investments in the US.

American executives from large companies such as General Electric will also follow Mr Trump and attend a separate business summit. White House officials have said in recent days that joint economic projects could be announced worth tens of billions of dollars. Foreign investment, particularly from US firms, is an important element in the Vision 2030 economic transformation plan led by Prince Mohammed to increase his country’s industrial base and non-energy private sector to reduce its dependence on oil production.

The defence sales and the economic investments serve what both countries perceive to be their respective most pressing interests. For Mr Trump, his goals are to hasten the defeat of ISIL and to contain Iran and reverse its regional gains, while working with traditional Arab partners in order to reduce US commitments and share more of the burden for regional security.

For Riyadh, the key symbolic and material outcome of the meetings with Mr Trump is a US commitment to counter its regional arch-rival Tehran, analysts said.

White House officials have reportedly described the creation of a Muslim "Nato" of regional countries – perhaps overlapping with the Islamic Military Alliance – as an idea they hope the weapons deal will help bring to reality. The Washington Post reported that they hope to begin laying down the framework and principles of such a US-assisted multinational military structure during the talks.

For Mr Trump such an alliance would serve the elusive goal shared by US presidents before him, including Barack Obama, of regional partners taking a greater share of security responsibilities.

Many of the deals included in the defence agreement are for big-ticket conventional items intended to deter Iran, such as warships and the Thaad advanced anti-missile defence system. But for many of the countries in attendance, the goal is greater coordination with and assistance from the US to counter with the changing threat from ISIL as the group is defeated in Iraq and Syria and potentially spreads elsewhere.

“This is an important and symbolic step to integrate an alliance of like-minded nations that are threatened by extremism and terrorist groups, and this could help kick-start a concept that is needed but an alliance that has only existed in name only,” said Sigurd Neubauer, a non-resident fellow at the Arab Gulf States Institute in Washington. “The question now is what will they do, how will they forge together and how will they carry out the next stages.”

Observers say the question of follow-through by the Trump administration, which is currently understaffed and mired in chaos that has frozen its domestic agenda, is key.

“The question is going to be how much bandwidth the US administration can devote to something like this. That is what is going to determine the success or failure” of plans for some sort of mutual defence treaty, said Muath Al Wari, a Gulf analyst at the Center for American Progress.

On Iran, Saudi Arabia hopes for a serious return to containment after an Obama administration it viewed as almost abetting Tehran’s rise. But Prince Mohammed and other Gulf leaders may be hoping for more than Mr Trump is able to give.

In Syria and Iraq, the US relies on allies and proxies of Iran to fight ISIL and Mr Trump is unlikely to take steps to confront them. In Yemen, the White House intends to provide more weapons to Riyadh but has not signalled any intention to enter the fight against Iran-backed Houthi rebels. “There is going to be some daylight between the rhetoric of taking on Iran and what’s actually happening,” Mr Neubauer said.

Other analysts, however, say that Iran has its own stake in defeating ISIL, independent of US interests. “Iran is not fighting ISIL because it’s good for America. Iran is fighting ISIL because it’s good for its equities in Iraq and Syria,” Mr Al Wari said.

During his campaign, Mr Trump vowed to shred the nuclear deal with Iran, but on Wednesday he waived additional US sanctions on Tehran, as stipulated under the deal.

Mr Trump has also called on Riyadh to carry more of the financial burden of the Syrian refugee crisis and people displaced from Mosul, providing troops to train anti-ISIL groups in Syria and reconstruction. But after agreeing to a large weapons deal at a time of budget deficits, Riyadh may be reluctant, the analysts said.

“The idea is that the Gulf wants the US closer to them on Iran, and the US wants the Gulf closer to them on ISIS,” Mr Al Wari added. “The best case scenario, according to both sides, is building up a clear and realistic front led by the US against Islamic extremism that bleeds into a similarly unified front against Iran.”

Mr Trump is taking the trip at an opportune moment in his four-month-old presidency. He is an increasingly beleaguered figure at home as his administration is engulfed in turmoil over revelations related to its alleged ties to Russia and potential obstruction of the related FBI investigation.

Mr Trump is a US president reluctant to travel out of his comfort zone, but eager for a policy win abroad that can recast, at least for a few news cycles, the narrative at home about his presidency, which even Republican allies have described as “a downwards spiral”.

To ensure success, the bilateral meetings have been meticulously planned and choreographed, but there are still risks that the president may stray off course.

While attending the inauguration of Saudi Arabia’s new Global Center for Combating Extremist Ideology with King Salman, Mr Trump is scheduled to give a televised address to Saudis about Islam and the need to counter extremism. The main speech writer is Stephen Miller, a young aide who has been a controversial critic of Islam and Muslims. But observers say they do not expect the speech to offend Saudi sensibilities – if Mr Trump can stay on script.

If Mr Trump is able to stay on track during his time in Saudi Arabia, Mr Neubauer said, it “could be a place where he finds success, at least in the short term”.