Prime Minister Jacinda Ardern has warned her ministers that New Zealand is at "greater risk" of another terrorist attack in the aftermath of March 15.

She also told the Cabinet that in order to bolster New Zealand's counter-terrorism efforts, more money may be needed in this year's Budget.

Ardern's comments came in a Cabinet paper she delivered in September last year, which was unclassified for the first time this week.

Its major focus was "preventing such a tragedy occurring again".

The paper examined how the Government could strengthen New Zealand against terrorism and violent extremism.

Also just publicly released were elements of the Government's updated Counter-Terrorism Strategy plan.

That plan involves details of new "tip-off messaging" due to unveil this April, which encourages the public to report any concerning behaviour they observe.

Next month marks one year since a gunman killed 51 people in two mosques in Christchurch.

The attack changed the political landscape of New Zealand and led to sweeping gun reforms and a Royal Commission of Inquiry.

Two weeks after the shooting armed police guard the Memorial Park Cemetery in Christchurch where a majority of the mosque shooting victims are buried.

In the September paper, Ardern said New Zealand was more susceptible to terrorist attacks than it was before March 15.

"Having experienced one incident, international evidence suggests we are at greater risk from a further attack – either inspired by the first or in retaliation.

"Within this context, the security needs of our communities are growing."

Ardern noted in the paper that the new "threat environment" has "possible financial implications" for officials tasked with keeping New Zealanders safe.

Even with some reprioritisation of resources, Ardern said, "There may be areas where additional resourcing is required."

Some extra funding from this year's Budget could be sought, she said, depending on what is recommended by the Royal Commission when it reports back in late April.

Ardern suggested Finance Minister Grant Robertson be put in charge of a ministerial task-force which would make sure any new Budget bids would be considered in a "holistic fashion".

She suggested that task force be made up of the Ministers for National Security, Police, GCSB and NZSIS, Customs, Immigration, Internal Affairs and Ethnic Communities.

Meanwhile, the Official Committee for Domestic and External Security Co-ordination (ODESC) – the Government's specialised committee which responds to national security threats – has publicly released its national strategic overview.

The document details how the Government would respond to another incident of terrorism and contains a timeline of new Government initiatives.

As well as the tip-off service, the document reveals that, in July, the NZSIS will release the first of an annual "unclassified threat environment report".