Tokyo's key Nikkei stocks index opened higher but immediately drifted lower Monday, as investors waited for the results of an emergency policy meeting at the Bank of Japan later in the day.
The Nikkei 225 index lost 0.92 percent or 159.97 points to 17,271.08 in early trade while the broader Topix index was down 0.95 percent or 11.97 points at 1,249.73.
Shortly before the opening bell, the BoJ announced it would hold a policy meeting at midday Monday, advancing the regular meeting set for Wednesday and Thursday.
The one-day meeting is to "discuss monetary control matters based on recent economic and financial developments," the bank said in a statement without elaborating further.
The news boosted stocks briefly at the open but buying soon waned.
"Since the Bank brought forward the meeting, there must be something for the markets," said Makoto Sengoku, market analyst at Tokai Tokyo Research Institute.
"We have to wait for the outcome but I'd be stunned if they decided to hold fire," he told AFP.
The US Federal Reserve on Sunday announced drastic emergency measures to shore up confidence and keep the financial sector running, including slashing the key interest rate to virtually zero.
The barrage of action came after a rally on Wall Street at the end of last week.
Wall Street stocks concluded a bruising week on a positive note Friday, rallying as President Donald Trump declared the coronavirus a national emergency and set the stage for more testing in the United States.
After initially being viewed as a China-centred problem, the virus has become a pandemic, raising fears of a global recession as major economies grind to a halt and professional sports leagues and entertainment events are cancelled.
The dollar has plunged since the Fed rate cut but recouped some losses on hopes for easing measures by the BoJ.
The greenback was changing hands at 106.85 yen early Monday against 108.02 yen in New York on Friday.
Toyota fell 1.00 percent to 6,023 yen while Sony rose 0.60 percent to 5,846 yen.
IT investor SoftBank Group lost 1.93 percent to 3,691 yen.