UPDATE 1-Treasury's Yellen says U.S. committed to market-determined exchange rate

(Adds quotes)

BONN, Germany, May 18 (Reuters) - U.S. Treasury Secretary Janet Yellen said on Wednesday the United States was committed to a market-determined exchange rate, after being asked by reporters about recent strengthening of the dollar.

Yellen told reporters ahead of a meeting of G7 finance ministers in Bonn that tighter U.S. monetary policy and risk aversion were factors favoring dollar strength, but having a market-determined exchange rate was "the best regime."

"The dollar is a global safe haven. And we tend to experience inflows naturally that push up the dollar in highly uncertain economic times," Yellen said. "So I think it's understandable that the dollar has risen." (Reporting by David Lawder Writing by Rami Ayyub; editing by John Stonestreet and Chizu Nomiyama)