The dollar jumped and the safe-haven yen reached its highest levels in a week after US President Donald Trump said he had tested positive for COVID-19 and begin a quarantine.
The news could cause a new wave of volatility in the market as investors prepare for the November presidential election.
The US currency rose nearly half a percent against the risk-sensitive Australian and New Zealand dollars, while the yen rose about 0.3% to 105.27 per dollar, its highest since Monday.
The euro fell 0.3% to $ 1.1716.
The yen gained against other currencies, in light of a widespread shift away from riskier assets and commodities. Trading volumes in Asia were thin due to holidays in China.
Trump said on Twitter that he and first lady Melania Trump had tested positive for the coronavirus and that they would be quarantined.