Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019. (Photos: Xinhua)

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Members of the U.S. Marine Band perform during the press preview of the White House Christmas decorations at the White House in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.

Christmas decorations are seen at the White House during the 2019 Christmas Press Preview in Washington D.C., the United States, on Dec. 2, 2019.