Melania Trump raised eyebrows after arriving in Saudi Arabia without a headscarf, two years after her husband criticised then-first lady Michelle Obama for not wearing one in the Muslim country.
Accompanying her husband on his first international trip, Mrs Trump stepped off Air Force One conservatively dressed in long sleeves and trousers to conform to the strict dress code that Saudi Arabia enforces for its female citizens.
But, critics noted she wasn’t wearing a head scarf.
Under the kingdom's strict dress code for women, Saudi women and most female visitors are required to wear a loose, black robe, known as an abaya, in public.
Most women in Saudi Arabia also cover their hair and face with a veil known as the niqab.
But covering one's head is not required for foreigners, and some Western women choose to forgo the headscarf. Theresa May and German Chancellor Angela Merkel both shunned head coverings during earlier visits.
Mrs Obama did not cover her head when she accompanied then-president Barack Obama on a condolence visit in January 2015 after the death of King Abdullah.
Mr Trump tweeted his displeasure over Mrs Obama's decision to appear bare-headed in 2015.
"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 (sic)," he tweeted.
Mr Trump's daughter Ivanka, a senior White House adviser who is accompanying her father, also did not cover her head.
