The dollar index slipped for a second straight day, edging down to a four-month trough amid concerns over a possible U.S. government shutdown due to problems with federal budget deal.
The dollar index sank 0.1 percent to 90.378 .DXY. It had slumped to a three-year low of 90.113 on Thursday and was on track to decline 0.65 percent on the week.
Versus the yen, the greenback lost 0.25 percent to 110.840.
The euro gained 0.2 percent to $1.2260 after rising about 0.45 percent overnight.
China's yuan touched the psychologically important 6.4 dollar level for the first time in more than two years amid solid economic figures in October-December.