Melania Trump arrived in Saudi Arabia without a headscarf as she joined her husband on his first foreign trip as president.
King Salman greeted the pair at the Royal Terminal of King Khalid International Airport in Riyad, alongside other senior officials from the Middle Eastern kingdom.
Like other recent female Western visitors, Ms. Trump did not cover her hair upon arrival in the conservative Islamic kingdom.
Earlier this year German Chancellor Angela Merkel opted not to do so.
Prime Minister Theresa May also decided not to eschew the dress code in the conservative country, saying she wanted to be a role model for oppressed women.
However, Donald Trump previously criticized former First Lady Michelle Obama for not wearing a headscarf during a visit to the Middle Eastern country.
In a 2015 tweet, he wrote: “Many people are saying it was wonderful that Mrs. Obama refused to wear a scarf in Saudi Arabia, but they were insulted. We have enuf enemies”.
Saudi Arabia has strict practices when it comes to women in public spaces: they are required to wear a full-length robe and cover their hair.
Some women wear a niqab – which covers their entire face with a veil.
These and other restrictive laws are in compliance with the guardianship system, which limits women’s movements and enforces a ban on female drivers.
Foreign visitors however are not forced to follow the regulations.
During his two – day visit, Mr. Trump is expected to make a speech urging Arab leaders to “drive out the terrorists from your places of worship” and will throw his support behind the country, while simultaneously criticizing the Assad regime in Syria for its “unspeakable crimes against humanity”, and Iran for contributing to its spiralling violence.
The US president will also likely announce a $350 billion (£268.5 billion) arms deal with Saudi Arabia – one of the largest of its kind in US history.