Wall Street was set to open lower, futures indicated, after New York-listed shares posted their biggest weekly decline since March.
"Another day, another reason to sell risk. Equity markets remain in a world of pain with everyone in search of a very elusive silver lining," said Stephen Innes at brokerage OANDA
MSCI's all-country index has spent four weeks in the red, despite intermittent rallies fueled by hopes of trade war detente. The pessimism has been exacerbated by data showing the world's largest economies -- the United States, China, Japan and Germany -- are all headed for slower growth.