Melania and Ivanka, who are accompanying Trump on his first global trip as President, were seen without headscarves during Trump?s key speech in front of heads of state in Saudi Arabia on Sunday.
National oil giant Saudi Aramco expects to sign $50 billion (38.36 billion pounds) of deals with US companies on Saturday, part of a drive to diversify the kingdom's economy beyond oil exports, Aramco's chief executive Amin Nasser said.
Obama called for understanding and acknowledged some of America's missteps in the region.
Melania, who is accompanying President Donald Trump on his first worldwide visit since entering office in January, told 200 female employees she tried to find balance between her role of First Lady and mother.
Almost three dozen heads of state and governments from Muslim-majority countries are in the Saudi capital for the Arab Islamic American Summit. They're not allowed to drive in the country, work with men, or get married without a male guardian's permission. In his Saudi speech, Trump condemned "Islamic extremism", "Islamists", and "Islamic terror", but not once uttered the precise phrase he pressed Obama on.
Trump made nearly no mention of Israel, his next stop on the tour Monday, leaving it off a list of countries fighting terror.
After two days of meetings here with Israeli officials and Palestinian Authority President Mahmoud Abbas, and visits to Jewish and Christian holy sites, Trump will fly to the Vatican to meet with Pope Francis, completing his tour of three religious capitals that he has said he wants to bring together in a new atmosphere of tolerance.More news: Ariana Grande returning to 'incredibly courageous city of Manchester' for benefit show
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Trump also devoted much of his speech to railing against Iran, accusing it of trying to destabilize the region.
Trump's trip to Saudi Arabia served as something of a reset with the region following his presidential campaign, which was frequently punctured by bouts of anti-Islamic rhetoric.
Trump did not make overt mentions of human rights abuses in Saudi Arabia or the other Gulf nations in his speech. He once mused that he thought "Islam hates us".
Earlier, CAIR urged Trump to use the event in Riyadh to clarify whether or not he respects Islam, and to avoid using "pejorative terminology" and "anti-Muslim stereotypes".
But he also made clear that he does not consider Muslim terrorists to be representing the religion of Islam as they wreak havoc that affects people of all faiths, including their own.
Trump arrived in Riyadh besieged by the fallout from his controversial decision to fire FBI Director James Comey and more revelations about the federal investigations into his campaign's possible ties to Russian Federation.