President Donald Trump walks with Saudi King Salman after a welcome ceremony at the Royal Terminal of King Khalid International Airport, Saturday, May 20, 2017, in Riyadh. (AP)

President Donald Trump and first lady Melania arrive for a welcome ceremony at the Royal Terminal of King Khalid International Airport, Saturday, May 20, 2017, in Riyadh. (AP)

US President Donald Trump (L) and Saudi Arabia's King Salman bin Abdulaziz al-Saud (R) stop for coffee in the terminal of King Khalid International Airport following Trump's arrival in Riyadh on May 20, 2017. (AFP)

Saudi Arabia's King Salman bin Abdulaziz Al Saud shakes hands with first lady Melania Trump during a reception ceremony in Riyadh, Saudi Arabia, May 20, 2017. (Reuters)

U.S. President Donald Trump and first lady Melania Trump arrive aboard Air Force One at King Khalid International Airport in Riyadh, Saudi Arabia May 20, 2017. (Reuters)

US President Donald Trump (C) holds a bouquet of flowers upon being welcomed by Saudi King Salman bin Abdulaziz al-Saud (unseen) during the former's arrival at King Khalid International Airport in Riyadh on May 20, 2017. (AFP)

Saudi Arabia's King Salman bin Abdulaziz al-Saud walks across the tarmac to greet US President Donald Trump at King Khalid International Airport in Riyadh on May 20, 2017. (AFP)

Children arrive with flowers for US President Donald Trump (C) during his welcoming by Saudi Arabia's King Salman bin Abdulaziz al-Saud (R), upon Trump's arrival at King Khalid International Airport in Riyadh on May 20, 2017. (AFP)

Saudi Arabia's King Salman bin Abdulaziz Al Saud (C) welcomes U.S. President Donald Trump (2nd L) with a coffee ceremony in the Royal Terminal after he arrived aboard Air Force One at King Khalid Airport International in Riyadh, Saudi Arabia May 20, 2017. (Reuters)

Saudi Arabia's King Salman bin Abdulaziz Al Saud meets with U.S. President Donald Trump and first lady Melania Trump during a reception ceremony in Riyadh, Saudi Arabia, May 20, 2017. (Reuters)

Saudi Arabia's King Salman bin Abdulaziz Al Saud and U.S. President Donald Trump have coffee during a reception ceremony in Riyadh, Saudi Arabia, May 20, 2017. (Reuters)

U.S. President Donald Trump, top right, accompanied by first lady Melania Trump, center, shakes hands with Saudi King Salman during a welcome ceremony at the Royal Terminal of King Khalid International Airport, Saturday, May 20, 2017, in Riyadh. (AP)

Saudi Arabia's King Salman bin Abdulaziz Al Saud welcome U.S. President Donald Trump during a reception ceremony in Riyadh, Saudi Arabia, May 20, 2017. (Reuters)

U.S. President Donald Trump, accompanied by first lady Melania Trump, smiles at Saudi King Salman, left, upon his arrival at a welcome ceremony at the Royal Terminal of King Khalid International Airport, Saturday, May 20, 2017, in Riyadh. Trump opened his first trip abroad since taking office, touching down Saturday in Saudi Arabia for a visit aimed at building stronger partnerships to combat terrorism in the region and moving past the controversies engulfing his young administration. (AP)