The dollar eased against the yen after U.S. launched missile strikes at an airbase in Homs, Syria on Thursday after Syrian forces allegedly carried out a chemical weapons attack earlier in the week.
The yen last traded at 110.40 against the greenback, down from session highs of up to 110.99 seen earlier. The Japanese currency is largely viewed as a safe-haven currency amid a risk-off environment.
The dollar was mildly lower at 100.64 against a basket of major currencies as of 11:40 am HK/SIN, but was still up at a nearly three-week high.
Against the yen, the Aussie was under pressure at 83.09 compared to highs of up to 83.7 earlier, and the New Zealand dollar traded at 76.89, down from the 77 handle seen on Thursday.
About 59 Tomahawk missiles form launched from U.S. navy warships in the eastern Mediterranean Sea, striking multiple targets including the airstrips, aircraft and fuel stations on the Shayrat Air Base, Reuters reported.
Facing his biggest foreign policy crisis yet, President Donald Trump said on Thursday U.S. time that he acted in America's "national security interest" against Syrian President Bashar al-Assad, who is backed by Russia and Iran.
The airstrike came amid Trump's closely-watched summit with Chinese President Xi Jinping in Florida.