Albright is welcomed to the conference

• Lauder: Every museum has Nazi plunder
• Victim art vs. trophy art
• U.S. offers 'principles and processes'
• Related stories and sites

WASHINGTON (CNN) -- U.S. Secretary of State Madeleine Albright told an international conference Tuesday that returning Nazi-seized artwork and other property to Holocaust victims and their heirs would "make the ledger slightly less out of balance."

Albright said that she learned only last year of her Jewish heritage and that her Czech grandparents and other relatives were victims of the Nazis. A refugee who came to the United States as a child, Albright was raised Roman Catholic.

Albright said that now, as a grandmother, she has begun to "think of the blood that is in my family veins."

"Does it matter what kind of blood it is?" she asked delegates at the Holocaust conference.

"It shouldn't. It is just blood that does its job," she said. "But it mattered to Hitler and that matters to us all, because that is why 6 million Jews died. And that is why this obscenity of suffering was visited on so many innocent, irreplaceable people."

Albright said archives around the world should open their files to researchers and the public so the Nazi loot can be tracked down and returned to the proper owners.

Among the governments and other groups represented at the conference was the Vatican, which has refused to open its files.

"We cannot restore life nor rewrite history," Albright said in opening the conference. "But we can make the ledger slightly less out of balance by devoting our time, energy and resources to the search for answers, the return of property and the payment of just claims."

The total value of Holocaust-era assets is not yet officially known.

Lauder: Every museum has Nazi loot

But Ronald Lauder, board chairman of the Museum of Modern Art in New York City, estimates that "50 percent --- 110,000 pieces of art worth $10 billion to $30 billion -- are still missing."

Lauder, who also heads the World Jewish Congress' art recovery commission, said "that every institution, art museum and private collection has some of these missing works."

And, he added, governments and museums should return the works or auction them to help Jewish groups.

"It is time for museums to set the same standard for ownership that they expect of themselves for authenticity," Lauder told delegates. "Is the art genuine? Is the art genuinely theirs?"

Russia, in a move the U.S. delegation called a breakthrough, pledged full cooperation in identifying and returning "victim art" looted by the Nazis.

Looted art was confiscated by Josef Stalin's troops after the war in what the then-Soviet state saw as reparations for damage caused and lives lost at the hands of Germany.

Victim art vs. trophy art

Moscow's representative, Valery Kulishov, asked for research help to separate "victim art" from "trophy art" -- or works that were originally owned by institutions rather than Holocaust victims.

Trophy art "is still an issue of great contention," said Elan Steinberg, executive director of the World Jewish Congress. Russia looks at that art as reparation for Nazi destruction of cultural property of the Soviets.

The emotionally explosive issue of reclaiming Nazi-seized assets has caused friction between Jewish groups, Switzerland, Russia, France and others.

Organizers of this conference strove to set a balanced tone, with Albright urging an "atmosphere free from threats" and saying "our goal must be justice ... we must dig to find out the truth."

U.S. offers 'principles and processes'

The United States on Tuesday distributed to delegates 11 proposed "principles and processes" on dealing with suspected Nazi-looted art, much now in government custody.

Under the guidelines, governments would agree to use resources and research to identify all Nazi-seized art that hasn't been returned to prewar owners or their heirs, making allowances for "unavoidable gaps or ambiguities in the provenance in light of the passage of time" and postwar confusion.

Nations and other groups also would publicize Nazi-confiscated art to try to locate prewar owners, as the French have done with more than 2,000 works listed on the Internet. Heirs would be encouraged to come forward.

And a central clearinghouse for the project would be considered, as well.

The U.S.-authored guidelines don't suggest compensation or a specific remedy.

Instead, they suggest: "A just and fair solution should be flexible and may vary according to the facts and other circumstances surrounding a specific case."

On the issue of life insurance, British delegate Anthony Layden said the conference is likely to support the idea of a global settlement of claims from families whose relatives died without collecting on wartime policies.

An international commission chaired by former U.S. Secretary of State Lawrence Eagleberger is already working with half a dozen major insurance companies on such a plan, and a $90 million humanitarian fund already has been launched.

Earlier this year, Swiss banks reached a $1.25 billion settlement with Holocaust survivors and Jewish groups over Nazi-looted gold, allowing attention to shift to the recovery of other assets.

The Associated Press and Reuters contributed to this report.