"Valuations have risen, and we could see greater volatility as a result, especially as the USA election closes in". They opened little changed in Hong Kong and slipped in Shanghai.
Australia's S&P/ASX 200 futures were down 0.22 percent and Hong Kong's Hang Seng index futures lost 0.08 percent.
MSCI's broadest index of Asia-Pacific shares outside Japan .MIAPJ0000PUS rose 0.5%, for a fourth straight day of gains, up almost 3% so far this year.
E-mini futures for the S&P 500 gained 0.11 percent.
In U.S. pre-market trading, Nikola Corp. dropped after Bloomberg News reported that the U.S. Securities and Exchange Commission is examining the company to assess the merits of a short-seller's allegations that the electric-truck maker deceived investors about its business prospects. Immunomedics Inc. nearly doubled after Gilead Sciences Inc. agreed to buy the cancer drugmaker for $21 billion.
Chinese blue chips added 0.4 per cent, buoyed by data showing China's industrial output rose 5.6 per cent in August from a year ago, expanding for a fifth straight month.
Investors remain on edge after the first consecutive weeks of declines since March for global stocks, amid a reassessment of valuations, volatility in options markets and uncertainty about a Covid-19 vaccine. The Fed is expected to maintain its dovish stance after earlier saying it will shift to a more relaxed approach on inflation.
"Market volatility is returning after months of steady advances in risk assets", BlackRock Investment Institute strategists led by Elga Bartsch said.
"We remain neutral stocks versus bonds as we balance extended equity valuations, fading fiscal support, and upcoming USA election risks against still ultra-low interest rates and a gradually improving economic environment", analysts at T. Rowe Price said in a global asset allocation report.
Elsewhere, the pound strengthened against peers as Prime Minister Boris Johnson faced a rebellion in Parliament against legislation that would override key elements of the divorce treaty signed with the European Union.
United States retail sales figures from August are due Wednesday.
Wednesday sees the FOMC policy decision and news conference from Chair Jerome Powell.
The Bank of Japan and the Bank of England announce their respective policy decisions on Thursday.
Friday sees quadruple witching for US markets when the quarterly expiration of futures and options on indexes and stocks happens on the same day.
S&P 500 futures rose 0.1% as of 9:05 a.m.in Tokyo. US West Texas Intermediate (WTI) crude futures were down 2 cents, or 0.1 per cent, at US$37.24 a barrel.
The yen was at 105.69 per dollar after appreciating 0.4%.The offshore yuan traded at 6.8079 per dollar, near the highest in 2020.The Bloomberg Dollar Spot Index was flat after dropping 0.3%.The euro was at $1.1868.The British pound traded at $1.2850 after gaining 0.5%.