With the talks between U.S. lawmakers on a plan to raise the government's $14.3 trillion debt ceiling before an August 2 deadline stalled, the dollar slid to a three-month low versus a currency basket with more falls seen likely if no deal is reached.
The Australian dollar was the main outperformer, surging 1 per cent to a fresh 29-year high of $1.1081 after stronger-than-expected Australian inflation data revived the chances of a further interest rate hike.
The Swiss franc and yen also gained strongly as investors sought perceived safer alternatives to the dollar, raising concerns about the possibility that Japanese authorities may intervene to stem yen gains.
Analysts polled by Reuters expect the United States will probably lose its top-notch AAA credit rating from at least one major rating agency, believing the wrangling over the debt ceiling has already damaged the economy.
EURO ZONE CONCERNS
The euro turned lower against the dollar, however, falling 0.25 percent to $1.4476 , having earlier climbed to a three-week high of $1.4537.
The euro's falls followed comments by German Finance Minister Wolfgang Schaeuble that Berlin was against a carte blanche for the euro zone's rescue fund to purchase bonds on the secondary market.