Investors are counting on even more spending in the United States, with White House negotiators vowing to work "around the clock" to reach a deal by the end of the week.
Markets also latched on to comments from the president of Federal Reserve Bank of San Francisco that the U.S. economy will need more support than initially thought, sending long-term Treasury yields into a downward spiral.
"Failure to agree to another round of stimulus would hit the U.S. economy hard at a time when high-frequency data suggests it is losing some momentum," said Tapas Strickland, analyst at Melbourne-based National Australia Bank.
The United States has reported more than 4.7 million coronavirus cases and over 157,000 deaths, the highest globally.
On Wednesday, MSCI's broadest index of Asia Pacific shares outside of Japan was flat near a 6-1/2 month peak at 560.36 points.
Japan's Nikkei was off 0.86% while Australia's benchmark index slipped 1%. Chinese shares fell too with the blue-chip CSI300 index down 0.8%, though it was not too far from a recent five-year peak.
South Korea's Kospi .KSII bucked the trend to hit its highest level since October 2018.
E-Mini futures for the S&P 500 was down 0.1%.
On Wall Street, the Dow ended up 0.6%, the S&P 500 rose 0.4% and the Nasdaq Composite added 0.4%.
"Significantly increased odds" of more monetary policy stimulus from the U.S. Federal Reserve is a key driver of equities although the rally has been reined in by stretched valuations, Mizuho analysts wrote in a note.
More central bank support is also dragging U.S. Treasury yields lower, led by the long-end of the curve, and helping "fire-up gold's glitter", they added.
GREENBACK UNDER PRESSURE
The dollar was under pressure USD= with the safe-haven Japanese yen rising to 105.66 as the bond market's dim view of the U.S. recovery sent real yields further into negative territory and nominal yields near record lows.
The risk-sensitive Australian dollar has risen more than 2% so far this year while the euro has climbed over 5% against the greenback.
The Aussie was last up 0.3% at $0.7184 while the common currency was inching toward a two-year high at $1.1812, buttressed by hardening perception that the U.S. rebound is lagging Europe.
Investors are now waiting for an Aug. 15 video conference where senior U.S. and Chinese officials are set to review a trade deal and likely air mutual grievances, according to sources.
China's U.S. envoy on Tuesday said Beijing does not want tensions to escalate.
In commodities, oil prices were a tad weaker with Brent crude off 8 cents at $44.35 a barrel. U.S. crude was down 11 cents at $41.59.
(Additional reporting by Chris Prentice in Washington; Editing by Stephen Coates and Himani Sarkar) ((firstname.lastname@example.org;))
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