New Zealand's kiwi was 0.3% lower at $0.6250, giving up an earlier gain of as much as 0.7%.
Over the weekend, the Federal Reserve, European Central Bank, Bank of England, Swiss National Bank, Bank of Canada and Bank of Japan announced joint action to enhance market liquidity.
The yen last traded at 131.79 per dollar , keeping intact a 2.5% gain from last week.
The euro was also about flat at $1.0668 and sterling was little changed at $1.21775, both erasing earlier small gains.
In cryptocurrencies, bitcoin took a breather after its surge to a nine-month high of $28,474 on Sunday, last trading 1.8% weaker at around $27,552.