OSWIECIM, Poland - A grim-faced President Bush toured the Auschwitz-Birkenau death camps on Saturday, pausing at the ruins of a Nazi crematorium to state his case for standing up to "evil" dictators and terrorism.

Sat May 31, 2:07 PM ET

US President George W. Bush speaks to reporters at Birkenau (Auschwitz II) prison camp as First Lady Laura Bush looks on.(AFP/Luke Frazza)

"Mankind must come together to fight such dark impulses," Bush said at the sprawling complex where Nazi German invaders committed genocide during World War II with assembly-line efficiency.

"These sites are a sobering reminder of the power of evil and the need for people to resist evil," he said.

Bush came to Poland citing the Holocaust as "one of the greatest lessons of the past" [...]

Nearly 1.5 million people, mostly Jews, were murdered in the twin camps of Auschwitz-Birkenau at the edge of the town now known by its Polish name Oswiecim. Jews regard Auschwitz as their biggest graveyard and the main symbol of the Holocaust.

Bush, the first sitting American president to visit the camp since Gerald Ford in 1975, led his entourage through the camp gate, which bears the sign: "Arbeit Macht Frei" (Work Sets You Free). That was the start of a march of death to the gas chambers of nearby Birkenau.

Bush stood beneath a sign that read: "Jews are a race which must be totally exterminated" and passed the barbed-wire fence that separated guards and their dogs from the prisoners.

In a squat brick building housing a gas chamber and crematorium, First Lady Laura Bush placed a long-stemmed rose on a cast-iron gurney used to load bodies into the ovens.

The Bushes saw a room piled high with human hair shorn from Auschwitz victims and used during the war to make textiles.

"So sad...very powerful," Bush said during the tour, his spokesman said.

Like his father, who visited the camp when he was vice president, Bush placed a wreath at the "Wall of Death" where some 25,000 people were shot.

The president and first lady paused for a moment of silence where the rail tracks came to an abrupt end in Birkenau. That is where prisoners were unloaded from railway cattle wagons by the thousands and sent to their deaths.

"The civilized world must never forget what took place on this site," Bush said after walking around the ruins of a crematorium destroyed by the Nazis in the final days of the war.

"Thank you sincerely for the deeply moving tour," he wrote in the guestbook. "In dedicating your lives to preserving the memory of the Holocaust and the martyrdom of Poles, you honor all who are victims here. May your work inspire future generations to stand ever vigilant against the return of such unspeakable evil to our world. Never forget."