European and US stock markets slid lower Tuesday despite promising signs that deadlocked stimulus talks in Washington are resuming ahead of the first debate between President Donald Trump and his challenger Joe Biden.

Markets elsewhere faced constant pressure as the coronavirus and the re-imposition of containment measures in several countries dampened sentiment.

"Stocks are in the red due to health concerns," commented David Madden, an analyst at CMC Markets UK.

Crude oil prices "are in the red as the overall bearish sentiment because of the health crisis has dampened demand prospects," he added.

In London, the FTSE 100 was off 0.5 percent at the close, while the Dow finished 0.5 percent lower, despite The Conference Board announcing a better-than-expected rise in September consumer confidence in the United States.

However markets shrugged off the consumer confidence surge, "with investors cautious ahead of tonight's first presidential debate," Charles Schwab investment bank said in a note.

Treasury Secretary Steven Mnuchin and House Speaker Nancy Pelosi for a second consecutive day negotiated over a long-deadlocked but much-anticipated stimulus package to rescue the battered US economy, a top aide to the lawmaker said, and agreed to keep talking.

Trump and former vice president Biden are set to hit the debate stage after a report in The New York Times claimed the president paid barely any federal income tax for years.

The "expose on Trump's tax affairs will certainly add extra spice to the evening, with the president going into the debate on the back foot, meaning he'll probably come out all guns blazing," remarked Craig Erlam, an analyst at the online brokerage Oanda.

New measures to stem the spread of the coronavirus also kept traders on their toes, as concern rises that a recovery from the near-global shutdown earlier in the year could be derailed, despite an International Monetary Fund spokesman saying last week the global downturn may not be as severe as predicted.

New York - Dow Jones: DOWN 0.5 percent at 27,452.66 (close)

New York - S&P 500: DOWN 0.5 percent at 3,335.47 (close)

Donald Trump and Joe Biden's first presidential debate comes as the president comes under pressure following a report saying he had hardly paid any taxes for several years
Donald Trump and Joe Biden's first presidential debate comes as the president comes under pressure following a report saying he had hardly paid any taxes for several years AFP / SAUL LOEB

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London - FTSE 100: DOWN 0.5 percent at 5,897.50 points (close)

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Paris - CAC 40: DOWN 0.2 percent at 4,832.07 (close)

EURO STOXX 50: DOWN 0.3 percent at 3,214.30 (close)

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