Prime Minister Jacinda Ardern says it is expected that all the bodies of victims of the two Christchurch mosque attacks will be returned to families by Wednesday.
A provisional list of missing people was released to families last night, but no formal list would be released until the victims had been formally identified, Ms Ardern said.
"I have had contact directly though with those directly on the ground and know that providing as much information as we can is incredibly important, but I also know the receipt of that provisional list last night will of course have been devastating."
Ms Ardern said the first victims' bodies would be returned to families from this evening.
Six disaster victim identification staff from Australia are helping with identifying victims, she said.
The attacks left 50 people dead, while 34 were still in Christchurch Hospital, with 12 in critical condition at the intensive care unit, Ms Ardern said.
A four-year-old girl was also in critical condition in Starship Hospital in Auckland.
She said there would be an increased police presence in Christchurch tomorrow to ensure public safety with an additional 120 police staff in the city.
There would also be a police presence outside mosques during opening hours and while they are in active use, which would continue while the police investigation continues, Ms Ardern said.
The National Management Crisis Centre was set up in Wellington yesterday, with staff on the ground in Christchurch to ensure all needs of victims and families are being met and to ensure a comprehensive and well coordinated response.
Ms Ardern said trauma support would be put in place in all Christchurch schools and early learning centres. The Christchurch office has a team of 200 staff mobilised which includes specialist staff coming from other parts of the country.
All regions have put staff with training for traumatic incidents on stand-by tomorrow. Schools and early learning centres elsewhere in the country have been made aware of available support, Ms Ardern said.
Cabinet will meet tomorrow and there will be preliminary policy discussions around issues such as gun policy, Ms Ardern said. She said regulatory changes take time, but she was looking to announce plans for any changes to gun policy as soon as possible.
Members of Parliament would pay tribute in the house on Tuesday. Condolence books would also be opened at Parliament and the National Library tomorrow.
Ms Ardern confirmed police had told her the accused Brenton Tarrant would face further charges.
She said the Australian born man would face the justice system in New Zealand for the terrorist attacks he is accused of, and she had sought advice about whether he would be deported to Australia at the end of the trial.
Ms Ardern said her office was one of more than 30 recipients of the killer's manifesto which was received only nine minutes before the attack was carried out, and which did not contain any location.
She said if anything could have been done to prevent the attack, it would have been done.