The New Zealand dollar has started the year on a strong note, but economists and strategists expect the currency to lose ground once the all-important US dollar picks up later this year.

Since late December, the Kiwi has been on a roll, rising by around 2 per cent against the greenback and coming close to US72c – a three-month high.

The currency spent last year oscillating in a wide US68c to US76c range, buffeted by the New Zealand election and volatility in the US dollar.

ANZ senior economist Phil Borkin said in some ways the kiwi's New Year strength reflected a typically thin trading period.


He said the currency's short-term gains were "not inconsistent" with the rally in other "risk" assets, especially global equities.

The US dollar has also been struggling, despite reasonable economic data, the passage of President Donald Trump's far-reaching tax bill, and expectations that the US Federal Reserve will increase its Fed funds rate twice this year.

But economists and strategists expect the kiwi's US dollar-inspired gains to be short-lived.

"We don't anticipate a lot of strength (in the kiwi) because we expect the New Zealand economy to go into transition, so growth will not be as wonderful as it has been," Borkin said.

Rate hikes from central banks around the world, alongside expectations that liquidity would start to move back to more normal, pre-GFC levels in the second half of 2018, would bring greater volatility and downward pressure on the kiwi, Borkin said.

He expects the currency to head lower by the end of the year to around the high US60s.

Westpac senior markets strategist Imre Speizer expects to see some short-term gains in the Kiwi as the year gets underway.

"In the near term, it goes higher, long-term - lower," Speizer said.

"The US dollar is struggling here," he said. Speizer expects the US dollar to stay on the back foot for the next few weeks, or possibly a month or two.

Speizer said that record-breaking runs on the US and other share markets suggested the international appetite for risk had been rejuvenated.

He said that, in turn, can have a dampening effect on the US dollar, which tends to gain when investors become risk-averse and seek safe havens.

Speizer expects the US dollar to reassert itself as the year progresses, putting downward pressure on the kiwi.

"Our view is that eventually, when the case for more Fed rate hikes becomes more compelling, then the US dollar will take more notice," he said.

To that end, Fed watchers will be focusing on US wage and inflation data to firm up the market's view that the central bank will lift rates.

Speizer expects to see the kiwi fall to US68c in the first half, falling possibly lower still to the mid US60s by the second.

However, given the market's current dynamic, he expects to see a run up to US75c over the next month or so.

ASB Bank chief economist Nick Tuffley takes a contrary view of the where the kiwi will be, based on his expectation that the US dollar will continue to weaken over the year.

He expects to see the kiwi at US75c by the year's end, based mostly on his view that the US dollar will continue to struggle.

Tuffley said much of the market's enthusiasm for Trump's rise to power in the November 2016 election was driven by expectations of large-scale pump priming of the US economy from the incoming administration, which so far has failed to materialise.

"It (the US dollar) is struggling to gain ground, despite the tax cuts," Tuffley said.

The Bank of NZ expects the currency to shift sideways throughout the year - not wandering too far beyond a US68c to US70c range.