Stocks across Europe finished lower on Friday, after a late-session slump on reports former U.S. national security adviser will testify about President Donald Trump. Markets had already opened in negative territory after U.S. lawmakers had trouble passing a long-awaited tax bill and pushed the vote back to Friday.

U.S. stocks ended lower on Friday after news surrounding former national-security adviser Michael Flynn added an element of political uncertainty into markets, though the issue wasn't seen as derailing a market rally that gave the Dow its best week of the year.

Asia-Pacific stock markets had a largely muted start to the week, though some buying built into midday, as investors mulled over the U.S. Senate's passing of a tax-reform proposal and the special counsel's probe of President Donald Trump's election campaign.