The New Zealand dollar gained ahead of a GlobalDairyTrade auction which is expected to deliver another increase in whole milk powder prices.
The kiwi rose to 73.23 US cents from 72.88 cents at 8am and 72.97 cents on Monday. The trade-weighted index increased to 78.09 from 77.86.
The local currency has been buoyed by the prospect of a fifth successive gain for whole milk powder on Fonterra's GDT platform, bolstering already growing optimism about the strength of New Zealand's economy.
AgriHQ analysts said the futures market indicates a 12 percent increase in WMP, with volumes expected to decline in coming months from earlier forecasts.
Dairy processor Synlait Milk raised its forecast payout for farmers when it reported earnings earlier this week, while investors anticipate Fonterra will deliver a strong result when it reports on Thursday.
"People don't want to sell ahead of the dairy auction because futures are saying it goes up," said Imre Speizer, senior market strategist at Westpac.
"That will already be priced in, but you might get a wee bit of a response [in the kiwi] at the time."
The dairy auction comes ahead of three central bank meetings, with the Bank of Japan set to review policy on Wednesday, followed by the US Federal Reserve and New Zealand's Reserve Bank on Thursday.
Westpac's Speizer said it's unclear whether the Bank of Japan will expand its quantitative easing programme, and a big surprise could see a large moment in the yen.
The kiwi was little changed at 74.53 yen from 74.46 yen.
The Fed isn't expected to raise the federal funds rate on Thursday, but stronger than expected inflation may tip the balance in favour of a hike later this year, while the RBNZ is expected to hold off raising the official cash rate until November.
New Zealand's two-year swap rate rose five basis points to 2.1 percent, and 10-year swaps increased four basis points to 2.62 percent.
The kiwi edged up to 96.99 Australian cents from 96.85 cents on Monday after minutes to the Reserve Bank of Australia's last policy review signalled rates were likely to remain stable over the coming months after two cuts earlier this year.
The local currency rose to 4.8834 Chinese yuan from 4.8656 yuan yesterday and increased to 65.52 euro cents from 65.32 cents. It gained to 56.15 British pence from 55.96 pence.