A year after a deadly quake killed 185 people and destroyed many structures in Christchurch, New Zealand, thousands of residents gathered to mourn the dead and celebrate the heroes that emerged Feb 22 last year.

Top officials from the NZ government, led by Governor-General Sir Jerry Mateparae and Prime Minister John Key, attended the Wednesday service that honoured the dead, according to the Australian Associated Press (AAP).

Prayers were offered by different religious groups while Mr Key was tasked with one of the day's readings that the attendees listened to, most of them donned in red and black shirts that marked the mood of the gathering.

Emergency crews who were first to the scene of the disaster were handpicked to recite each of the names of the victims who perished when the magnitude 6.3 earthquake hit the city, AAP said.

Christchurch Mayor Bob Parker expressed his gratitude for all the people and nations that came to Christchurch's rescue at a time the then devastated city needed it most.

On that note alone, Parker said that Christchurch had established a link with the parties that extended their assistance last year.

"We will never forget the things that you have done for us,' the Christchurch mayor was reported by AAP as saying.

The city chief executive also acknowledged that Christchurch will never be the same city after the tremor that altered its landscape and its spirit.

"We can never be the same again," Parker said.

Christchurch has now become a city for heroes, Parker stressed, as he called on city residents to work as a team and rise up from the ruins and build a new city that is only fit for heroes that were ironically spawned by a disaster.

"We've learned that when we work together, when we listen to each other, extraordinary things can happen," the mayor said.

"We are seeing a resurgence of strength and spirit, we are learning a new way to do things ... No city has ever been more strongly united in wanting to recover, rebuild, and once more be a great place to live and to work," Parker added.