WASHINGTON/RIYADH, May 16 (Reuters) - When U.S. President Donald Trump meets Saudi princes in Riyadh on Saturday, he can expect a warmer welcome than the one given a year ago to his predecessor Barack Obama, who Riyadh considered soft on arch foe Iran and cool toward a bilateral relationship that is a mainstay of the Middle East's security balance.
Beneath the pomp, Riyadh will be looking for assurances that the Trump administration will continue its notably harsher tone toward Iran and keep up pressure, through both rhetoric and action, to stop what Saudi Arabia sees as Tehran's destabilizing activities in the region.
The U.S.-Saudi alliance has experienced turbulence since Riyadh faulted what it saw as Obama's withdrawal from the region, a perceived tilt toward Iran since the 2011 Arab uprisings and a lack of direct action against Syrian President Bashar al-Assad, an Iranian ally.
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Saudi Arabia will also want to showcase high-profile investment deals with American companies to show progress on its ambitious "Vision 2030" economic and social reform agenda, while Washington says U.S. arms sales arms worth tens of billions of dollars are in the pipeline.
Trump's visit to Saudi Arabia is the first stop on his maiden international trip since taking office in January. U.S. and Saudi officials are eager to highlight the powerful symbolism of an American president choosing to visit the birthplace of Islam as his first stop rather than to neighbors Canada or Mexico.
Besides meeting with Saudi officials, Trump will also meet with leaders of the six-nation Gulf Cooperation Council (GCC) and have lunch with leaders of more than 50 Muslim countries.
Critics have accused Trump of being anti-Muslim after he issued a ban, now blocked by U.S. courts, on entry into the United States by citizens of several Muslim-majority countries, citing national security concerns.
U.S. public opinion of Saudi Arabia has never fully recovered since the Sept. 11, 2001 attacks in which 15 of the 19 hijackers were Saudi. The U.S. Congress last year passed the Justice Against Sponsors of Terrorism Act, a law permitting lawsuits holding Saudi Arabia responsible for the attacks. The Saudi government has long denied involvement.
Trump's visit "sends a clear message that the U.S. is standing with its close allies in the region and that they're not abandoning them," a senior Saudi official told Reuters, reflecting the view many Gulf leaders had of Obama, who they considered had made securing a nuclear deal with Iran a higher priority than the U.S.-Gulf alliance.
Obama's visit to Saudi Arabia in April 2016 was overshadowed by Gulf Arab exasperation with his approach to the region, and doubts about Washington's commitment to regional security.
"This (new) administration comes in and ... says, 'No, wait a minute, Iran is active,'" the official said, referring to Gulf states' views of Iran's involvement through proxies in regional conflicts in Syria, Iraq, Bahrain and Yemen.
The Trump administration has called the nuclear agreement with Iran "the worst deal ever negotiated," and senior administration officials have repeatedly criticized Iran's behavior for its support for Assad, its ballistic missile activities and its support for militant groups in the region.
Mustafa Alani, the director of security and defense at the Jeddah-based Gulf Research Center think tank, said that beyond U.S. rhetoric, Gulf leaders would like to see "America classify Iranian-supported militias as terrorist groups."
SUPPORT IN YEMEN
Saudi Arabia will also be looking for further U.S. support in the war in Yemen, where a Saudi-led coalition has been fighting the loosely Iran-aligned Houthi group and troops loyal to former President Ali Abdullah Saleh to restore the internationally recognized government to power.
The Obama administration backed Saudi Arabia when it launched air strikes in Yemen in March 2015 but grew sour as it saw the number of civilian casualties grow and curtailed some military support to Riyadh.
By contrast, "we don't get criticized about the war in Yemen" by the Trump administration, the senior Saudi official said.
In Trump's meeting with GCC leaders, the discussion will revolve around how to strengthen the structures of the group, which includes Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates, to be more effective, a senior White House official said.
The Republican U.S. president along with first lady Melania Trump will dine with Saudi royal family members. Trump, known for his penchant for Twitter, will participate in a Twitter forum with young people, National Security Advisor H.R. McMaster said on Tuesday.
Trump will deliver a speech on "the need to confront radical ideology" and participate in the inauguration of a new center intended "to fight radicalism and promote moderation," McMaster said.
While Trump has criticized Saudi Arabia for not paying enough for U.S. military support, he has been silent since becoming president about its religious conservatism. Traditional Wahhabi doctrine is ultra-conservative, imposing a strict version of Islamic law and urging resumption of early Muslim practices.
Critics of the kingdom say the government does not do enough to prevent the teachings of some of its ultra-conservative clergy from fanning militancy overseas as well as a domestic security threat at home.
Radicalization of Muslims in the world's top oil exporter has led to domestic attacks and the involvement of Saudi citizens in jihadist movements in Iraq and Syria.
The senior clergy have denounced militant Islamic doctrines, such as those of al Qaeda or Islamic State, but still preach intolerant views.
An inaugural Saudi-U.S. CEO forum will be held in Riyadh on Saturday in which several deals are expected to be signed in defense, electricity, oil and gas, industrial and chemical sectors. New licenses for U.S. companies to operate in the Kingdom also will be issued.
Saudi Deputy Crown Prince Mohammed bin Salman, the king's son, is the face of "Vision 2030" and is eager to showcase the kingdom's success a year since its inception.
The CEO of state oil giant Saudi Aramco is expected to sign deals with top U.S. companies to promote local manufacturing.
General Electric Co is due to sign several memoranda of understanding. Saudi Basic Industries Corp and U.S. oil company Exxon Mobil Corp are also expected to sign a protocol agreement to develop their joint chemical project in Texas, a source close to the matter said.
The White House official said the kingdom was in the final stage of negotiating a $100 billion arms deal.
A New York Stock Exchange delegation is also expected to visit Saudi Arabia after Trump to try to lure a listing by Aramco, slated for 2018 and worth about $100 billion. World stock exchanges are vying for slices of Aramco's initial public offering, expected to be the largest in history, with Hong Kong currently the frontrunner among bourses in Asia because of its strategic links to key Saudi oil importer China.
The NYSE delegation will have tough competition as rival exchanges tweak regulation to become more attractive options.
(Reporting by Yara Bayoumy in Washington and Katie Paul in Riyadh; Additional reporting by Reem Shamseddine in Jeddah and Steve Holland and Mike Stone in Washington; Writing by Yara Bayoumy; Editing by Will Dunham)