U.S. President Donald Trump and Lebanese Prime Minister Saad al-Hariri (not pictured) attend a joint press conference in the Rose Garden of the White House in Washington, U.S., July 25, 2017.

U.S. President Donald Trump attends a press conference accompanied by Lebanese Prime Minister Saad al-Hariri (not pictured) in the Rose Garden of the White House in Washington, U.S., July 25, 2017.

U.S. President Donald Trump and Lebanese Prime Minister Saad al-Hariri attend a joint press conference in the Rose Garden of the White House in Washington, U.S., July 25, 2017. REUTERS/Carlos Barria - RTX3CVTJ

U.S. President Donald Trump and Lebanese Prime Minister Saad al-Hariri attend a joint press conference in the Rose Garden of the White House in Washington, U.S., July 25, 2017. REUTERS/Carlos Barria

Lebanese Prime Minister Saad al-Hariri attends a joint press conference with U.S. President Donald Trump (not pictured) in the Rose Garden of the White House in Washington, U.S., July 25, 2017.

U.S. President Donald Trump and Lebanese Prime Minister Saad al-Hariri attend a joint press conference in the Rose Garden of the White House in Washington, U.S., July 25, 2017.

White House senior advisor Jared Kushner and Ivanka Trump attend a joint press conference between U.S. President Donald Trump and Lebanese Prime Minister Saad al-Hariri in the Rose Garden of the White House in Washington, U.S., July 25, 2017.

U.S. President Donald Trump speaks during a press conference with Lebanese Prime Minister Saad al-Hariri in the Rose Garden of the White House in Washington, U.S., July 25, 2017.

U.S. President Donald Trump shakes hands with Lebanese Prime Minister Saad al-Hariri during a press conference in the Rose Garden of the White House in Washington, U.S., July 25, 2017.

U.S. President Donald Trump and Lebanese Prime Minister Saad al-Hariri attend a joint press conference in the Rose Garden of the White House in Washington, U.S., July 25, 2017.