The U.S. dollar hovered below a one-week high on Thursday and Asian stock markets were broadly mixed as investors braced for three days of potentially market-moving news from the Federal Reserve's annual symposium in Jackson Hole.

The Nasdaq fell as megacaps lost, after having rallied for much of the year. Nvidia fell 3.5%, the biggest drop in nearly four months.

The U.S. dollar was little changed on Wednesday as traders awaited a speech from Federal Reserve Chair Jerome Powell at the annual Jackson Hole central bankers' symposium later this week for clues on the path of monetary policy.

Investors are tracking talks aimed at ending the Russia-Ukraine war and awaiting Federal Reserve Chair Jerome Powell's speech at Jackson Hole at the end of the week.