US Secretary of State John Kerry warned Syria it would face action over the "moral obscenity" of a chemical weapons attack, as expectations grow that Washington and its allies are preparing to launch a punitive missile strike.

Hong Kong stocks fell 0.24 percent, while Sydney fell 0.08 percent with sentiment hurt also by poor Australian earnings results. Surfwear retailer Billabong International plunged 10.6 percent while Seven Group dived 9.6 percent.

Tokyo stocks were flat by the morning break as bargain-hunting helped erase early losses.

"Lower futures (contracts), a lower dollar, lower Wall Street stocks, and the heightened probability of an internationalised Syrian conflict should send the market at least modestly lower today," said SMBC Nikko Securities analyst Hiroichi Nishi.

Shanghai shares were also flat in morning trade, slipping 0.01 percent, as the market took a breather following a rise of nearly two percent the previous session, dealers said.

Singapore was down 0.70 percent and Taiwan fell 0.29 percent. Seoul gained 0.34 percent.

Oil prices rose over fears of renewed instability in the Middle East. New York's main contract, West Texas Intermediate for delivery in October, rose 57 cents to $106.49, and Brent North Sea crude for October added 45 cents to $111.18.