A sharp fall in the value of the yen has pushed the Australian dollar lower against the greenback.
Tthe currency was trading at at $US104.15c in later afternoon trading, down from $US104.41c late yesterday.
Commonwealth Bank currency strategist Peter Dragicevich said news of Japan's massive quantitiave easing program had boosted the US dollar against all major currencies since Thursday afternoon.
"That demand for the US dollar has weighed on all currencies against the US dollar," he said.
The Bank of Japan yesterday announced it intended to spend seven trillion yen ($69.88 billion) a month buying assets such as Japanese government bonds as it tries to stimulate growth after two decades of stagnation.
Mr Dragicevich said the Australian dollar had risen sharply against the Japanese yen, pushing past the 100 yen level for the first time since August 2008.