US President Donald Trump (R) shakes hands with visiting Italian President Sergio Mattarella during a joint press conference at the White House in Washington D.C., the United States, on Oct. 16, 2019. (Photo by Ting Shen/Xinhua)

US President Donald Trump (R) shakes hands with visiting Italian President Sergio Mattarella during a joint press conference at the White House in Washington D.C., the United States, on Oct. 16, 2019. (Photo by Ting Shen/Xinhua)

US President Donald Trump (R) shakes hands with visiting Italian President Sergio Mattarella during a joint press conference at the White House in Washington D.C., the United States, on Oct. 16, 2019. (Photo by Ting Shen/Xinhua)

US President Donald Trump (R) shakes hands with visiting Italian President Sergio Mattarella during a joint press conference at the White House in Washington D.C., the United States, on Oct. 16, 2019. (Photo by Ting Shen/Xinhua)