Asian markets mostly fell on Friday following a sell-off on Wall Street as traders fear US lawmakers will fail to pass much-vaunted tax cuts.

Tokyo's Nikkei was among the biggest losers, even with data showing Japanese business confidence at an 11-year high, while the euro struggled to recover from a disappointing European Central Bank meeting.

Wall Street stocks fell Thursday on reports that Republican senator Marco Rubio was considering voting against a final tax cut deal if certain demands were not met.

The warning comes as at least two other members of his party remain uncertain about how they will vote, putting its wafer-thin majority in peril.

The surprise loss of the Republicans' once-safe Alabama seat this week has added to the sense of fear and once again raises questions about Donald Trump's ability to push through his economic agenda.