Prime Minister John Key says he can assure the families of the men who died in the Pike River Coal mine that everything that could have been done to save them was done.
Mr Key says the country is in mourning and all New Zealanders are ready to stand side by side with the families.
He also acknowledged that families in Australia, Britain and South Africa have lost loved ones in the tragedy.
Flags are flying at half-mast nationwide on Thursday as a mark of respect for the 29 men who lost their lives.
Pike River is the country's worst mining tragedy since an explosion killed 43 men in Huntly in 1914.