"I think [Trump] is acting like another Hitler by inciting racism," wrote Schloss, an Auschwitz concentration survivor. "During his U.S. presidential campaign he has suggested the 'total and complete shutdown of Muslims entering the United States,' as well as pledging to build a wall between the U.S. and Mexico to keep illegal immigrants out."
Schloss added, "If Donald Trump became the next president of the U.S. it would be a complete disaster."
Schloss, who was once a Jewish refugee in Amsterdam, wrote the criticism of Trump as part of a larger opinion piece for International Holocaust Remembrance Day (Jan. 27).
This year's theme was "Don't stand by." Schloss noted the theme was "particularly important now with the refugee crisis going on as more people than ever are being bystanders."
The 86-year-old said the refugee "situation today is worse than it was under Hitler because at that time all the Allies -- the U.S., Russia and Britain -- worked together to combat the terrible threat of Nazisim," but such is not the case in the fight against terrorism today.
"I am very upset that today again so many countries are closing their borders," she wrote. "It is even harder for today’s Syrian refugees who have a very different culture. We were Europeans as well as Jews -- we were assimilated."
She added, "I remember how upset the world was when the Berlin Wall was erected in 1961 and now everybody is building walls again to keep people out. It’s absurd."
Schloss is the daughter of Erich Geirginger and Elfriede Geiringer. Her father died in Auschwitz, and her mother -- who survived -- later remarried to Otto Frank, the father of Anne Frank.
Donald Trump's campaign did not immediately respond to ABC News' request for comment.