The New Zealand dollar rose as the greenback weakened against most major currencies following the last-minute approval of the U.S. budget, while the rampant strength of the Australian dollar also helped underpin the kiwi.

The US currency came under renewed pressure amid uncertainty surrounding government funding. On Friday, Republicans and Democrats managed to hammer out a last minute agreement to temporarily fund federal operations until the end of the year, but still set the stage for a showdown later in the year.

The dollar index, a measure of the greenback against a basket of six currencies, fell 1 per cent from Friday to 75.68.

"A lot of focus was on whether the U.S. government would shutdown but in end they managed to avert it," said Khoon Goh, head of market economics & strategy for ANZ New Zealand.

"However that's only one potential negative taken out of the equation, the prevailing theme for the US dollar is still continued weakness.

The New Zealand dollar also drew renewed support from the Australian dollar, which rose to a new post-float high against the US currency of US$1.0582, before paring back to US$1.0546.

"You just have look to where interest rates are, and Australia is a standout among G-10 countries," Goh said.

"The carry is attractive on the Aussie, and it is benefitting from flows from investors who are after yields."

The kiwi rose to 78.24 US cents from 78.10 cents in New York on Friday, and was little changed at 68.01 on the trade-weighted index of major trading partners' currencies from 67.99.

It fell to 74.09 Australian cents from 74.15 cents last week, and fell to 66.53 yen from 66.57 yen.

It fell to 54.11 euro cents from 54.18 cents on Friday, and rose to 47.78 pence from 47.63 pence previously.

China, the world's second-largest economy, posted its first quarterly trade deficit in seven years, according to the customs bureau.

That was on the back of a surge in imports which rose 32.6 per cent to $400.7 billion in the quarter, leaving the country with a deficit of $1.02 billion in the first three months of the year compared with a surplus of $13.9 billion a year earlier.

The kiwi may trade between 77.70 US cents and 78.50 cents, Goh said, with the currency having now completed a 100 per cent retracement from its February highs.