JERUSALEM — Democratic presidential contender Senator Obama toured Israel’s Holocaust memorial today, laying a wreath in memory of the 6 million Jews who died and saying, “Ultimately, this is a place of hope.”

Mr. Obama toured the Yad Vashem Holocaust memorial on a Jerusalem hillside as he moved through a busy day of meetings with Israeli and Palestinian Arab officials, including Prime Minister Olmert and the president of the Palestinian Authority, Mahmoud Abbas.

The Democratic nominee-in-waiting is on a tour of the Middle East and Europe, a journey financed by his campaign and designed to reassure skeptical voters back home of his ability to serve as commander in chief and guide diplomacy after eight years of the Bush administration.

Mr. Obama drew an unusually warm welcome from President Peres, who said his greatest wish is for a “great president of the United States. That is the greatest promise for us and the rest of the world.”

“God bless you,” the 85-year-old fixture of Israeli politics, who joked that he was speaking as one young man to another, said. Obama is 46.

At the Holocaust memorial, Mr. Obama wore a white skullcap as he laid a wreath in memory of the victims of the Nazis.

Later, he said: “I am always taken back to sort of the core question of humanity that the Holocaust raises. That is, on the one hand, man’s great capacity for evil, and on the other hand, our ability to come together to stop evil.”

He added, “So despite this record of monumental tragedy this ultimately is a place of hope because it reminds us of our obligations and responsibilities hopefully to raise a better future for our children and our grandchildren.” He said he hoped he could bring his two young daughters with him on his next trip.

In signing the guestbook, he wrote, “May we remember those who perished, not only as victims but also as individuals who hoped and loved and dreamed like us, and who have become symbols of the human spirit.”

Earlier today, Mr. Obama held a breakfast meeting with the Israeli Defense Minister, Ehud Barak. Neither man spoke to reporters as they posed for news cameras at the plush downtown King David Hotel before sitting down to a breakfast of smoked salmon and local cheeses. After the Barak meeting, Mr. Obama met the opposition leader, Benjamin Netanyahu.

Mr. Barak’s office issued a laconic statement saying the two discussed “all the relevant issues” and the “future challenges facing Israel and the region” — which meant they most likely discussed Israeli-Palestinian Arab peace efforts and Israel’s determination that Iran not be allowed to build atomic bombs.

Mr. Netanyahu told reporters those same two subjects were discussed in his meeting with Mr. Obama.

“The senator and I agreed that the primacy of preventing Iran from becoming a nuclear power is clear, and this should guide our mutual policies.”

Many people in Israel are concerned that Mr. Obama — a first-term American senator with little foreign policy experience — would push Israel too hard in negotiations with the Palestinian Arabs.

But Mr. Netanyahu said Mr. Obama told him that “he would never seek in any way to compromise Israel’s security, and that this would be sacrosanct in his approach to political negotiations.”

At the King David Hotel, an “Israel for Obama” campaign poster was draped over an armchair in the lobby. The poster included Mr. Obama’s campaign slogan — “Change you can believe in” — in Hebrew.

Some Israelis who support Mr. Obama hope he will take a stronger hand with Israel when it ignores its commitments to America to halt settlement building and dismantle settlement satellites known as outposts.

“In general, I think tough love is better than a free hand,” the head of the Israel for Obama campaign, Samson Altman-Schevitz, said. He moved to Israel two years ago from Chicago, where Mr. Obama’s wife, Michelle, was his adviser at the University of Chicago.

Aides said that while at the Holocaust Memorial, Mr. Obama met briefly with the Israeli border police officer, Aml Ganim, who shot and killed the Palestinian Arab man who used a bulldozer yesterday to try and overturn cars outside the King David Hotel.

Mr. Obama arrived in Israel last night from neighboring Jordan and is due to leave for Germany early tomorrow.