The New Zealand dollar pushed higher overnight but was unable to hold onto its gains.

By 8am today the kiwi was buying US68.53c, little changed from its level at 5pm yesterday.

According to Reuters data it climbed to US68.86c during the night, an 11-month high just above the high point reached a week or so earlier.

ANZ bank said the markets were extremely wary of taking the NZ dollar into new territory and were thwarted on every attempt to push higher. Flat equity markets had removed some momentum this morning.

Despite a weak domestic fundamental backdrop, the NZ dollar had been rising on signs of improving global activity, better risk appetites and a US dollar that had been shunned, ANZ said.

The NZ dollar continued to find those willing to back it further after already spectacular gains from this year's low.

"Arguments abound as to the fundamentals, which to this point have been largely ignored in favour of what is happening with the USD," ANZ said.

"Expect further shunning of local fundamentals at this point, but for how long, reasonable followers of the currency will ask."

The NZ dollar opened locally at 64.79 yen, slightly down from the local close, but edged up to 0.4794 euro and to A81.77c against the Australian dollar. The trade weighted index was 63.67 at 8am from 63.58 at 5pm.

The US dollar edged up against the euro and yen in extremely thin trade as Wall Street surrendered early gains and traders adjusted positions ahead of US consumer and housing data due this week.