Dow Jones Industrial Average futures hovered around the flatline, indicating a slight decline of 12.60 points. S&P 500 and Nasdaq 100 futures also pointed to slight losses at the open.
The U.S. and China held talks on Wednesday that are set to continue into Thursday, but observers did not have high hopes after President Donald Trump said he did not "anticipate much" to be resolved, in an interview with Reuters.
Domestic political news also weighed on sentiment, amid legal troubles surrounding Trump's former personal attorney Michael Cohen and ex-campaign manager Paul Manafort. Trump on Wednesday lashed out at Cohen, saying he wouldn't advise seeking the lawyer's services.
The legal troubles have raised questions about whether Trump will remain in office. In an interview with "Fox and Friends," Trump said: "If I ever got impeached, I think the market would crash. I think everybody would be very poor."
"Because without this thinking, you would see numbers that you wouldn't believe in reverse," Trump said, pointing at his head. "I got rid of regulations. The tax cut was a tremendous thing."
Nevertheless, the current U.S. bull market has found its way into the history books, becoming the largest on record, spanning 3,453 days.
Leading central bankers are due to meet for an economic symposium at Jackson Hole in Wyoming on Thursday, where they will discuss the future of monetary policy. Federal Reserve Chair Jerome Powell will address attendees in a speech Friday.
In economic data, weekly jobless claims figures are due at 8:30 a.m. ET, while flash Composite Purchasing Managers' Index (PMI) data are due at 9:45 a.m ET.