"To this day, there are those who insist that the Holocaust never happened -- a denial of fact and truth that is baseless and ignorant and hateful," Obama said Friday during a visit to the camp with German Chancellor Angela Merkel and Holocaust survivor and Nobel Peace Prize Laureate Eli Wiesel. "This place is the ultimate rebuke to such thoughts, a reminder of our duty to confront those who would tell lies about our history."
About 56,000 people, mainly Jews, were worked as slaves or killed in gas chambers at the former concentration camp during World War II.
"This place teaches us that we must be ever-vigilant about the spread of evil in our own time, that we must reject the false comfort that others' suffering is not our problem," Obama said, "and commit ourselves to resisting those who would subjugate others to serve their own interests."
Words are inadequate to convey what is felt when seeing "the suffering inflicted so cruelly upon so many people" at concentration and extermination camp during World War II, Merkel said.
"We, the Germans, are faced with the agonizing question how and why, how could this happen, how could Germany wreak such havoc in Europe and the world?" she said. "It is therefore incumbent upon us Germans to show an unshakable resolve to do everything we can so that something like this never happens again."
Wiesel, who was liberated from Buchenwald, said the concentration camp provided a memory "of bringing people together."
"Memory must bring people together, rather than set them apart ... not to sow anger in our hearts, but on the contrary, a sense of solidarity with all those who need us," he said.
Obama and Merkel conducted bilateral talks on a range of subjects before visiting Buchenwald.
Obama, who arrived in Paris late Friday, is scheduled Saturday to mark the 65th anniversary of D-Day -- June 6, 1944, when Allied forces invaded Europe in the campaign to defeat Adolf Hitler.