The New Zealand dollar fell to a three-week low ahead of the European Central Bank meeting, which may see the region's central bank firm up plans for more stimulus, and as US employment numbers loom.

The kiwi fell as low as 77.36 US cents, the lowest since Nov. 12, trading at 77.46 cents at 5pm in Wellington from 77.55 cents at 8am and 77.71 cents yesterday. The trade-weighted index declined to 79.08 from 78.13.

The ECB is expected to keep rates unchanged when it reviews policy on Thursday in Brussels, though investors will be watching president Mario Draghi to see whether he gives any further hints on plans to inject stimulus into the regional economy. That comes ahead of US non-farm payrolls figures on Friday, which are likely to show the world's biggest economy is continuing to recover. The prospect of a more active ECB and a strong US economy continued to bolster the greenback, which is at its highest level since March 2009.

"Early indications are pointing to a strong non-farm payrolls, which would be supportive for the US dollar, and there's growing expectations the ECB will move on some sort of stimulus, which is negative for the euro and translates into a strong US dollar," said Martin Rudings, senior dealer foreign exchange at OMF in Wellington.

Rudings said the kiwi was also being weighed on by weaker than expected Australian economic data yesterday, which has fuelled speculation the Reserve Bank of Australia may cut interest rates next year, and a drop in global dairy prices ahead of the anticipated lowering of the forecast payout to farmers for the 2015 season.

That's also put next week's Reserve Bank of New Zealand meeting in view, with governor Graeme Wheeler expected to rein back the forecast track for future interest rate hikes.

"There appears to be quite a big window where the RBNZ wont' have to move on rates at all, so they'll use that window to put pressure on the currency as an additional tool to verbal intervention," Rudings said. "The most likely outcome is when the Federal Reserve raises rates, we're going to sit there and do nothing for a few rate hikes, so naturally the interest differential between New Zealand and the US will narrow and that should have the currency coming off."

The kiwi increased to 62.93 euro cents from 62.72 cents yesterday, and fell to 49.40 British pence from 49.66 pence. It declined to 92.30 Australian cents from 92.56 cents yesterday, and increased to 92.87 yen from 92.73 yen.