Eyes are also on the start this week in China of the Communist Party's 18th congress, which will see a once-in-a-decade leadership transition.
Tokyo softened 0.36 percent, or 32.29 points, to 8,975.15, Seoul rose 1.05 percent, or 19.95 points, to 1,928.17 and Sydney closed 0.24 percent, or 10.7 points, higher at 4,484.8.
Hong Kong slipped 0.28 percent, or 61.97 points, to 21,944.43 while Shanghai closed down 0.38 percent, or 8.03 points, at 2,106.00.
Tuesday's US poll sees President Barack Obama and his Republican challenger Mitt Romney neck-and-neck, leaving markets in a tight band as traders hold off making any bets until the outcome is known.
"Players remain on edge, as the outcome is simply too close to call," said Hiroichi Nishi, general manager of equities at SMBC Nikko Securities.
Wall Street closed Monday slightly higher.
The Dow gained 0.15 percent, the S&P 500 advanced 0.22 percent and the Nasdaq added 0.59 percent.
A downbeat set of data on activity in the US services sector weighed on sentiment in New York.
The Institute for Supply Management reported its purchasing managers index for the non-manufacturing sector dropped to 54.2 in October from 55.1 in September. Most analysts had forecast a decline to 54.5.
Anything above 50 is considered growth while anything below is seen as a contraction.
In Europe an official said finance ministers of the 17-nation eurozone were unlikely to make a formal decision on the installment batch of crucial bailout cash for Greece next week, despite the fact Athens will likely run out of money this month.
Athens will hold crucial votes this week on a fresh round of austerity demanded by international lenders, while the country is gripped by a new wave of strikes.
The global uncertainty weighed on the euro, which fell to its lowest level in two months against the dollar during New York trade.
The euro bought $1.2771 in afternoon Asian trade against $1.2791 late Monday in New York, where it had briefly hit $1.2767, its weakest since September 11.
The euro also fetched 102.39 yen against 102.69 yen, while the dollar was trading at 80.13 yen against 80.28 yen.
And the Australian dollar rose to $1.0422 from $1.0359 on Monday after the country's central bank said it would keep interest rates on hold.
Oil prices edged lower. New York's main contract, light sweet crude for delivery in December, shed 14 cents to $85.51 a barrel while Brent North Sea crude for December delivery fell 29 cents to $107.44.
Gold was at $1,691.55 at 1025 GMT compared with $1,679.75 late Monday.
In other markets:
-- Taipei rose 51.32 points, or 0.71 percent, to 7,236.68.
Leading smartphone maker HTC gained 3.35 percent to Tw$200.5 while Hon Hai Precision was 2.63 percent higher at Tw$89.8.
-- Manila rose 0.29 percent, or 15.79 points, to 5,473.61.
-- Wellington rose 0.50 percent, or 19.41 points, to 3,927.67.
Air New Zealand surged 3.75 percent to NZ$1.25 and Fletcher Building added 1.9 percent to NZ$7.13 while Fisher & Paykel Appliances shed 0.4 percent to NZ$1.27.
-- Singapore closed down 0.41 percent, or 12.36 points, at 3,019.33.
Sembcorp Marine fell 5.97 percent to Sg$4.41 and Keppel Corp shed 2.78 percent to Sg$10.50.
-- Kuala Lumpur was 8.41 points lower, or 0.51 percent, at 1,645.63.
British American Tobacco fell 2.6 percent to 59.84 ringgit, Maxis shed 2.5 percent to 6.74 and AirAsia lost 2.3 percent to 2.98.
-- Jakarta ended up 0.26 percent, or 11.33 points, at 4,314.27.
Lender BCA rose 3.0 percent to 8,500 rupiah and cement maker Semen Gresik climbed 1.4 percent to 14,750 rupiah.
-- Bangkok fell 0.45 percent, or 5.86 points, to 1,300.84 Banpu slid 0.26 percent to 388.00 baht, while PTT Plc dropped 0.93 percent to 319.00 baht.
-- Mumbai rose 0.29 percent, or 54.51 points, to 18,817.38 points.
Indian drug giant Cipla increased 4.18 percent to 396.35 rupees while private housing finance firm HDFC rose 1.75 percent to 782.35 rupees.