The US dollar declined against most major currencies amid thin trading in holiday season.
In late New York trading on Monday, the euro increased to $1.0921 from $1.0862 in the previous session, Xinhua reported. The Australian dollar rose to $0.7187 from $0.7186.
The US dollar bought 121.05 Japanese yen, lower than 121.28 yen of the previous session. The US dollar fell to 0.9919 Swiss franc from 0.9928 Swiss franc, and it went up to 1.3964 Canadian dollars from 1.3928 Canadian dollars.
The dollar index, which measures the greenback against six major peers, was down 0.33 percent at 98.375 in late trading.
With no major data coming out of the country on Monday, the US dollar retreated from its two-week highs at the beginning of a shortened trading week when the US and most European markets will close on Friday for Christmas.