01/04/2005 AT 06:00 PM EST
Supermodel Heidi Klum and British singer Seal are engaged to be married, the crooner confirmed to PEOPLE.
"I proposed on Dec. 23 at 14,000 feet in Whistler, B.C., in uncharted terrain on a glacier, in a natural snow cave, in an igloo built just for the moment," Seal tells PEOPLE. Whistler is a ski resort town in the western Canadian province of British Columbia.
The German supermodel, who also announced the engagement on her Web site Tuesday, calls the proposal: "a once-in-a-lifetime event."
The couple has been romantically linked for about a year even though Klum was pregnant by her ex-boyfriend, Italian racing team owner Flavio Briatore, 55. In May, she gave birth to a daughter, Leni. Her five-year marriage to hairstylist Ric Pipino ended in 2002.
Klum's engagement to Seal (real name: Sealhenry Samuels) was also confirmed by her father, Guenther, speaking to the Express in Cologne, Germany. The newspaper also said that after the engagement the couple flew to sunny Mexico, where Seal owns a house.
Only last month, Klum, 31, said her relationship with Seal, 41, hadn't progressed to the point of a discussion of marriage, but she did say she wants more children.
She also said then that she and Seal had definite plans for the holidays. "A mixture of hot and cold, skiing and sun-bathing," she said. "But where – that remains a secret."