The greenback fluctuated between gains and losses, last trading flat after snapping a three-day winning streak on Monday, with the U.S. dollar index last at 97.36. Powell will speak on the economic outlook later on Tuesday and some central bank policymakers renewed focus on inflation risks in remarks on Monday, prompting a slight easing of wagers on a rate cut by the Fed next month. Money markets are currently pricing in a near-90% chance of a rate cut in October, down slightly from 92% a day earlier, per CME's FedWatch tool. Congressional funding talks this week to avert a government shutdown on September 30 have added to market jitters. "It's a slightly hawkish tone from Fed speakers that has given people a little bit of pause for thought," said Tony Sycamore, market analyst at IG in Sydney.