The dollar hit a session low against a basket of major currencies Monday as Federal Reserve Chair Janet Yellen delivered prepared remarks about the U.S. economy.
Yellen struck a generally positive tone on the U.S. economy on Monday — despite last week's disappointing jobs report.
Speaking at an event in Philadelphia, Yellen continued to say the Fed needs to raise rates, but she stepped back from putting a time period on that plan.
The Fed funds rate probably needs to rise gradually over time, she said, and hikes should come before all of the central bank's economic goals have been fully reached.
The dollar index hit a session low of 93.85, before trading at 93.93. Against the euro, the dollar pared gains, with the common currency last trading 0.03 percent higher at $1.1367.
Earlier on Monday, having hit more than three-week lows against a basket of major currencies after a poor employment report prompted investors to rule out the chance of a hike in U.S. interest rates in June.
Friday's data showed nonfarm payrolls increased by only 38,000 jobs last month, the fewest in more than 5-1/2 years, confounding forecasts for a rise of 164,000 jobs.
Investors have almost priced out the chance of a rate increase at the Fed Reserve's June 14-15 policy review, and reduced the likelihood of a July rate hike to around 30 percent from around 60 percent.
With worries about a British exit from the European Union, or Brexit, also gathering, investors are increasingly uncertain whether the Fed will raise rates in the near term.
"Rate hike expectations for June have disappeared. And while the focus has shifted to July, we expect the dollar to be rather subdued this week, with not much of economic data out of the U.S.," said Yujiro Goto, currency strategist at Nomura.
"Dollar/yen should trade in a 105-110 yen range while the euro will be in a $1.10-$1.15 range."
Against the , the dollar slid to a one-month low of 106.35 on Friday, before bouncing back to trade 0.82 percent higher at 107.43 yen on Monday, thanks to bargain-hunting after its big fall late last week.
With the yen near an 18-month peak of 105.55 hit in early May, some traders were also wary of threats of intervention from Japanese authorities. Japan's vice finance minister for international affairs, Masatsugu Asakawa, stuck to his usual comments on Monday that he was closely watching movements in currency markets.
"With the UK referendum looming, it's arguable that considerable risk capital is sidelined for now and keeps euro/dollar within the range," said John Hardy, head of currency strategy at Saxo Bank.
Meanwhile, sterling fell more than 1 percent to a three-week low after a slew of polls pointed to the "Leave" camp leading ahead of the June 23 vote on whether Britain stays in the European Union or not.
The pound was 0.4 percent lower at $1.4454 after having fallen to as low as $1.4352 in Asian trade, its lowest since May 16.
—CNBC's Everett Rosenfeld contributed to this report.