The New Zealand dollar slipped from a four-month high as traders mulled a later start to Federal Reserve tapering of monetary stimulus and as the greenback clawed back some ground following better economic data.

The kiwi rose as high as 84.35 US cents overnight, and was trading at 83.74 cents at 8am in Wellington, from 83.88 cents at the 5pm market close on Thursday. The trade-weighted index edged up to 77.97 from 77.86.

The greenback recovered some ground following a slump after the Federal Reserve unexpectedly chose to keep its $US85 billion ($NZ101.58 billion) a month stimulus programme unchanged this month as it awaits more data showing a revival in the world's largest economy.

Better than expected US data on jobless claims, home sales and Philadelphia business activity helped arrest the greenback's decline.

"Markets spent most of the night in a kind of stunned silence as investors continue to assess the implications of yesterday's decision," Mike Jones, currency strategist at Bank of New Zealand, said in a note. "A smattering of upbeat US data did throw the US dollar something of a lifeline."

Following the Fed's decision, BNZ has revised higher its forecast for the New Zealand dollar and now expects it to end the year at 83.50 US cents, with the TWI at 79.

In New Zealand reports are due for August job advertisements, net migration and credit card spending.

The New Zealand dollar jumped to a four-month high of 83.67 yen early on Friday morning as investors favoured higher-yielding assets over so-called safe havens like the yen. The kiwi was trading at 83.27 yen at 8am in Wellington from 82.50 yen at the 5pm market close on Thursday.

The local currency rose to a one-month high of 88.72 Australian cents, and was trading at 88.71 cents at 8am in Wellington from 88.41 cents at the 5pm market close.

The kiwi was little changed at 61.92 euro cents from 61.99 cents and rose to 52.24 British pence from 52.02 pence.