The New Zealand dollar touched a month-low against the US dollar as the greenback broadly strengthened on optimism about the US economy and after the Bank of Japan upped its stimulus plans.

The kiwi traded at 77.64 US cents as at 5pm in Wellington, unchanged from the start of the day and down from 78.41 cents in late local trading on Friday. The local currency traded at 87.52 yen, from 87.59 yen at 8am and from as high as 88.03 yen, highest since Sept. 25, in New York on Friday.

US government figures on Friday are expected to show American employers added about 235,000 jobs in October, while the jobless rate held at a six-year low of 5.9 percent, according to a Bloomberg survey. A strong labour market underlines expectations it is a matter of when not if the Federal Reserve begins raising interest rates next year.

The yen was broadly weaker after the BOJ on Friday said it would raise its asset buying programme to 80 trillion yen a year, from a previous rate of 60-70 trillion yen, in an attempt to encourage more lending and boost spending. Japanese banks were closed on Monday for the Culture Day holiday.

"The kiwi remains fairly downbeat," said Imre Speizer, senior market strategist at Westpac Banking Corp. US data and the Bank of Japan "are fresh catalysts."

Speizer said traders are watching to see whether the kiwi breaks below a key support level of 77.09 US cents.

In a BusinessDesk survey of 11 traders, strategists and brokers, seven predict the kiwi will fall this week, while three expect it to rise and one says it will likely remain at current levels. The New Zealand dollar has declined 12 percent since its peak in July as a revival in the US economy increases demand for the greenback.

The New Zealand dollar increased to 88.93 Australian cents from 88.83 cents on Friday. The kiwi almost unchanged at 62.20 euro cents from 62.21 cents on Friday and fell to 48.62 British pence from 49.02 pence. The trade-weighted index was at 76.50 from 76.56 on Friday.