Risk-aversion underpinned the dollar near a two-month high against a basket of other currencies of 80.843 hit on Monday, while pressing the euro down 0.1 percent to $1.2782, near Monday's two-month low of $1.2767, Reuters reported.
The MSCI index of Asia-Pacific shares outside Japan was nearly unchanged, pulled higher by a 0.3 percent rise in Australian shares and a 0.2 percent increase in South Korean shares, but countered by weakness in most other Asian equities.
Hong Kong's Hang Seng Index fell 0.6 percent, dragged down by a drop in the index heavyweight HSBC Holdings. Japan's Nikkei fell 0.4 percent.
If the U.S. election is too close to call in a number of states and the result is delayed, it could roil markets as the protracted 2000 election battle did. Analysts have said Barack Obama's re-election is perceived as negative for equities, while markets see Mitt Romney as stock-friendly, according to Reuters.
U.S. crude futures were down 0.1 percent at $85.59 a barrel and Brent inched up 0.2 percent to $107.92.
Asian credit markets were subdued with investor risk aversion intact, leaving the spread on the iTraxx Asia ex-Japan investment-grade index little changed from Monday.