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People attend the centennial commemoration of the birth of Raoul Wallenberg in Sigtuna, Sweden, on Saturday.

The 100^th anniversary of Swedish diplomat Raoul Wallenberg’s birthday was celebrated Saturday with a call for a day on the Swedish calendar to honor the man who saved thousands of Jews during World War II but whose own fate remains a mystery.

“Wallenberg is an excellent symbol for a Sweden and Europe with solidarity, openness and tolerance,”  Democracy Minister Birgitta Ohlsson wrote in an opinion piece in Dagens Nyheter.

Wallenberg, born Aug. 4, 1912, has been remembered throughout the year thanks to efforts of a Swedish national committee established to draw attention to his life and deeds, Ohlsson wrote. However, she argued, his work “deserves an annual Swedish remembrance.”

Attila Kisbenedek / AFP - Getty Images file

A Hungarian woman touches the memorial stone of late Swedish diplomat Raoul Wallenberg in St. Istvan park of Budapest, Hungary, on Wednesday.

 Several memorial celebrations were planned in Stockholm on Saturday, with guests including Crown Princess Victoria attending a memorial for Wallenberg.

In May, Sweden issued a postage stamp honoring Wallenberg.

But Ohlsson wrote that she is worried the memory of Wallenberg could fade.

“In a country where anti-immigrant parties are gaining ground, right-wing movements are formed and populist groups become more visible, it is increasingly important that each nation talks about the individuals who make a difference for humanity,” she wrote.

International memorials
Wallenberg was remembered internationally.

President Barack Obama on July 27 signed the Raoul Wallenberg Centennial Celebration Act, passed by Congress to honor the diplomat with the Congressional Gold Medal. The U.S. mint is now authorized to design and print the medal, which will be presented in the Congress, according to a White House statement.

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On Friday in Moscow, about 50 people -- including members of the Jewish community, historians, and rights workers -- gathered for a somber commemorative ceremony in Moscow's Memorial Synagogue at the Holocaust and Jewish Heritage Museum, according to Radio Free Europe. Diplomats from Sweden, Hungary, the Netherlands, Germany and Israel were among those who spoke. A new documentary film on the secret services was shown.

Other events were held in Israel and Hungary.

Fate unclear
As Sweden's envoy to Hungary during the war, Wallenberg, then age 32, prevented the deportation of 20,000 to as many as 100,000 Jews to Nazi concentration camps by issuing them protective Swedish government passports.

Wallenberg also talked occupying German officers out of a plan to obliterate Budapest's Jewish ghetto.

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Wallenberg was last seen on Jan. 17, 1945, in Budapest, when he drove off to meet Soviet authorities to discuss protection for Jews once the Red Army drove out the Nazis. Soviet intelligence agents abducted the Swedish diplomat.

Reports of his death are inconsistent.

The Soviet Union claimed that Wallenberg, incarcerated at Moscow's Lefortovo prison, died on July 17, 1947, of a heart attack, the New York Times wrote in 2000. However, he reportedly was interrogated six days after the date Russia claims Wallenberg died, according to others studying his case. A special commission investigating victims of Russian leader Joseph Stalin's political terror said he was executed at Lubyanka prison at KGB headquarters.

"The family wants now to get the truth," says Cecilia Ahlberg, Wallenberg's great-niece, said Friday in a BBC interview in which Wallenberg's half-sister, Nin Lagergren, 91, agreed.

"We want all the facts about his whereabouts in the Soviet Union, what happened and when it happened," Ahlberg said.

This article includes reporting by NBC News' Jim Gold.

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