UPDATE: Finance Minister Grant Robertson expects the official inflation figure to rise when it is released later this week.

The Reserve Bank earlier this month stepped up the battle against inflation with an increase of half of a percentage point in the Official Cash Rate (OCR) to 1.5 per cent, with a warning that further rises are coming.

Food prices were 7.6 per cent higher in March than the year before - the biggest annual increase in more than a decade.

With the inflation figure for the first quarter due to be announced on Thursday, Robertson is unwilling to speculate on what the figure might be but says inflation has not peaked yet.

Robertson told Morning Report all commentators are predicting an increase in the inflation figure this quarter, and potentially the second quarter as well.

"I expect that it will be rising as it is right around the world.

"The amount that it rises by is obviously what everyone is debating."

He says the cut in the fuel excise duty and road user charges may keep inflation in check but it's a global phenomenon driven by supply chain constraints, the impacts of Covid-19 and the war in Ukraine.

In the US and UK the inflation rate has now topped eight per cent.

He agrees some households are facing a crisis with the rise in prices for food and petrol.

A substantial package from the government that took effect on April 1 to help low and middle income households, plus the cut in the fuel excise duty, was relieving some of the pressure, he says.

The package provided significant increases for those on Income Support and people receiving the Family Tax credit, with the fuel initiative adding some more relief.

Winter energy payments begin on May 1 for those on the lowest incomes plus superannuitants, he said.

He rules out removing GST from some food items.

"I acknowledge this is a challenging time for many people but it's hard to come through a 100-year economic shock caused by Covid without some impacts."

Robertson says Prime Minister Jacinda Ardern's first overseas trip in two years is very significant.

Singapore and Japan are New Zealand's fourth and fifth biggest trading partners, so the trip is a chance to talk trade and tourism with the prime minister accompanied by representatives of the dairy, energy, food and technology sectors.

"It's a great opportunity to get out there and sell New Zealand."

In Japan there is a chance to explore opportunities around renewable energy, building on cooperation between companies in the two countries on hydrogen.

"We think there's a real opportunity for us to partner with a very large market there on how those technologies develop."

It's the beginning of several trips that Ardern and Ministers will make as the country reconnects with the world.

He disputes Export New Zealand's view that the country has become a hermit kingdom, and says the export sector has played its part with some support from the government in helping New Zealand to prosper through the pandemic.

EARLIER:

Mortgage interest rates have hit 6 percent for four-year fixed terms.

Finance Minister Grant Robertson speaks to Morning Report about rising rates and inflation.

The Reserve Bank of New Zealand (RBNZ) earlier this month stepped up the battle against inflation with an increase of half of a percentage point in the Official Cash Rate (OCR) to 1.5 percent, with a warning that further rises are coming.

Food prices were 7.6 percent higher in March than the year before - the biggest annual increase in more than a decade.

More to come...

-RNZ.