Wall Street was likewise headed for a lackluster start, with the futures contract for the Dow Jones Industrial Average up less than 0.1 per cent at 25,543.00 and the S&P 500 future contract down 0.1 per cent at 2,736.70.
The Shanghai Composite index slipped 0.2 per cent to 2,659.36 and Hong Kong's Hang Seng bounced back, gaining 0.7 per cent to 26,120.96. Australia's S&P ASX 200 advanced 1.0 per cent to 5,875.20. Shares fell in Taiwan but rose in Jakarta and Thailand.
Financial markets have been on a roller-coaster ride and the election Tuesday could roil things further.
US midterms, votes on lawmakers and other officials that fall between presidential elections, are often marked by low voter turnout. But political watchers are expecting voter angst over which party will control the US House and Senate to drive more Americans to cast votes. Asia will be watching to see how the vote might influence US. trade, economic and security policies.
"US midterms may not spring any shocks in terms of who wins control of what but investors are understandably taking a cautious approach ahead of the results, given how markets have been over the last month," Craig Erlam of OANDA said in a commentary.
Keeping hopes alight for resolving a punishing trade war between the two biggest economies, a Chinese vice president, Wang Qishan, said at a conference in Singapore that Beijing is ready to discuss issues with the Trump administration.
Benchmark U.S. crude slipped 28 cents to $62.82 per barrel in electronic trading on the New York Mercantile Exchange. It lost 4 cents to $63.10 a barrel on Monday.
Brent crude, used to price international oils, dropped 51 cents to $72.66 per barrel.
The dollar rose to 113.29 yen from 113.20 yen. The euro climbed to $1.1414 from $1.1408.