"My greatest thanks goes to the Norwegian people, who appeared responsible when needed, who kept their dignity, who chose democracy," he told a ceremony in a packed Norwegian parliament.

The event, attended by King Harald V and his son Crown Prince Haakon, saw members of Norway's parliament -- the Storting -- observed a minute of silence before striking up Norway's national anthem, "Ja, vi elsker," meaning "yes, we love" in English.

While the Norwegian flag flew at half-mast on the building, parliament speaker Dag Terje Andersen read out the names of all the victims of the attacks claimed by far-right extremist Anders Behring Breivik.

A national day of commemoration will be held on August 21 for the victims, their loved ones and those who reached out to help them, Stoltenberg announced.

"The generation of July 22 is one of heroes and hope," he said.

"Thanks to them, we can turn to the future with a renewed belief in our fundamental values and with the hope that the seed of dialogue and tolerance takes root," he said.

A total of 77 people were killed when Behring Breivik opened fire at a retreat of the Labour Party's youth wing on Utoeya island, and by a bomb he set off near the headquarters of the Labour-led government in central Oslo.

Copyright AFP (Agence France-Presse), 2011