"This 'hard Brexit' scenario has largely been priced by markets with the pound falling around 20 percent since the Brexit vote, although further falls could be on the cards depending on Theresa May's speech," said Peter Cavanaugh, an adviser at Bancorp Treasury Services.
US financial markets are closed on Monday for Martin Luther King Jr. Day. Globally, two speeches by Federal Reserve chair Janet Yellen, the inauguration of US President Donald Trump and a slew of corporate earnings including from Morgan Stanley and Citigroup, the Federal Reserve's Beige Book survey, and the European Central Bank's policy review will draw the focus in the coming days. New Zealand economic releases this week include the food price index for December, which will help economists conclude their inflation forecasts for the fourth quarter, surveys of business and consumer confidence and building consents for November.
The trade-weighted index slipped to 78.22 from 78.30.
The kiwi fell to 94.79 Australian cents from 94.98 cents on Friday in the US. It fell to 4.9041 yuan from 4.9152 yuan and fell to 81.17 yen from 81.63 yen.
The local currency was little changed at 66.94 euro cents from 66.98 cents.