The kiwi was at 83.16 US cents at 5pm, down from 83.61 US cents at 5pm on Tuesday.
The focus is on a statement by the US Federal Reserve's Open Market Committee (FOMC) at 8.15am New Zealand time on Thursday, and the cash rate review by the RBNZ at 9am.
"The RBNZ will need to be careful that it does not again pressure the New Zealand dollar higher with inferences of eventual higher interest rates, as it did in December," Derek Rankin at Rankin Treasury said.
The RBNZ is widely expected to hold the cash rate at 2.5 per cent.
Imre Speizer, senior markets strategist at Westpac, said the RBNZ's comments may be more dovish than the last press release in December, which could cause a little kiwi selling.
The FOMC may reaffirm that stimulatory programmes will be kept in place after mumbles previously of a possible exit.
"I'd expect (Fed chairman Ben) Bernanke to say parts of the economy have improved but parts are still a bit questionable. That might cause US interest rates to dip. That's a potential up for the kiwi," Mr Speizer said.
The kiwi was unchanged at 80.16 Australian cents from the same level at 5pm on Tuesday and was up against the Japanese currency at 76.27 yen from 76.08.
It was at 62.22 euro cents from 62.16.
The trade-weighted index was at 75.37 from 75.62.