Asian shares fell on Wednesday as a United States warning to Americans to prepare for the possibility of a coronavirus pandemic drove another Wall Street tumble and pushed yields on safe-haven Treasuries to record lows.

The S&P 500 and the Dow Jones Industrial Average both shed more than 3 percent on Tuesday in their fourth straight session of losses.

That led MSCI's broadest index of Asia-Pacific shares outside Japan down 1.28 percent. Japan was among the worst-performing markets in the region, weighed by growing concerns the virus could cancel the Tokyo Olympics.

Yields on 10-year and 30-year US Treasuries teetered near record lows and gold rose as worries about the economic effects of the virus outbreak boosted safe-haven assets.

The World Health Organization says the epidemic has peaked in China, but concern that its spread is accelerating in other countries is likely to keep investors on edge.

"What we are seeing is share markets are playing catch-up," said Michael McCarthy, chief market strategist at CMC Markets in Sydney.

"Other asset markets have been flashing warning signs for weeks. A corrective bounce in equities is possible, but we still have a lot of downward momentum."

Chinese shares fell 1.3 percent. Shares in South Korea, which has been rattled by a sudden rise in virus infections, briefly hit a two-month low.

While the stock rout has been global, the recent pace of selling in Asia has not been as severe as it has on Wall Street, which has been hit hard by the escalation of virus cases outside of Asia.

The S&P 500 lost $2.14 trillion in market capitalisation over the last four sessions, according to S&P Dow Jones Indices analyst Howard Silverblatt.

US stock futures rose 0.2 percent in Asia on Wednesday, but that did little to brighten the mood.

Adding to recent fears was an alert from the US Centers for Disease Control and Prevention on Tuesday warning Americans to prepare for the spread of coronavirus in the US, signalling a change in tone for the Atlanta-based US health agency.

The virus has killed almost 3,000 people in mainland China but has spread to dozens of other countries. Of increasing concern to investors, however, is the rising death toll in other countries.

Drastic travel restrictions slammed the brakes on China's manufacturing and consumer spending and there are worries other countries will face similar disruptions.

The virus has also hit Japan's stocks hard on rising worries it could lead to cancellation of the 2020 Summer Olympics scheduled to start in Tokyo in July.

Japan's Nikkei stock index slid 1.1 percent, while shares of Japan's Dentsu Group Inc, an advertising agency deeply involved in the planning and operation of the games, fell to a seven-year low on Wednesday.

Shares of sportswear makers and other companies related to the Olympics have also fallen recently.

The yield on benchmark 10-year Treasury notes traded at 1.3421 percent on Wednesday in Asia, close to a record low of 1.3070 percent. The 30-year yield stood at 1.8142 percent, above a record low of 1.7860 percent.

The decline in yields weighed on the US dollar. The greenback was last quoted at 110.25 yen, continuing a pullback from a 10-month high of 112.23 yen.

The US dollar traded at $1.0872 per euro, off an almost three-year high of $1.0778 reached on February 20.

Spot gold rose 0.53 percent to $1,643.75 per ounce as investors sought safe havens.

Oil prices recovered some recent losses in Asia but there are lingering concerns that expected output cuts by the biggest oil producers will not be enough to offset a decline in global energy demand caused by the virus.

US crude ticked up 0.96 percent to $50.38 a barrel. Brent crude rose 0.78 percent to $55.38 per barrel. The Organization of the Petroleum Exporting Countries (OPEC) and allies including Russia, a group known as OPEC+, have been sending signals that they will cut output further.

However, oil could come under more pressure as weekly US supply reports due later on Wednesday are expected to show a rise in inventories, according to a Reuters poll.