Trump calls Nazi Holocaust 'history's darkest hour'

U.S. President Donald Trump paid tribute at Israel's Yad Vashem memorial on Tuesday to the six million Jews killed in the Nazi Holocaust, calling it an indescribable act of evil.

Holding hands, the president and First Lady Melania Trump walked solemnly to lay a wreath together upon the ashes of Holocaust victims, buried at the site's Hall of Remembrance. 

"Words can never describe the bottomless depths of that evil, or the scope of the anguish and destruction. It was history's darkest hour," Trump said in a short speech after the memorial ceremony.