The children were working with a private investigator but have few legal options to prevent the overseas burial, publicist Danny Deraney told The Associated Press.
Teruyuki Olsen, a lawyer for Jean Kasem, did not return an email seeking comment. As the spouse of the radio personality, she is conservator of his body, said Deraney, who works for Kerri Kasem.
It was unclear when the burial might occur and why Jean Kasem selected Norway.
Kasem, the host of "American Top 40," died on June 15 at a hospital in Gig Harbor, Washington. He was 82 and suffering from dementia. His death followed a lengthy battle over his care between Jean Kasem and his three adult children from his first marriage.
Deraney said burial outside the United States would be contrary to what Casey Kasem had wanted.
"He publicly made it clear to his friends, his kids, that he wanted to be buried in Forest Lawn in Glendale, in Los Angeles," the publicist said.
The Norwegian newspaper VG reported that Kasem will be buried in Oslo.
"It's been arranged, he's going to Oslo," Wenche Madsen Eriksson, the head of the funeral service administration in Oslo, told the newspaper.
She declined to say why Oslo was chosen, explaining that the family wants to keep that information confidential.