The benchmark Nikkei 225 index was down 2.20 percent or 476.53 points at 21,202.15 in early trade, while the broader Topix index was down 1.88 percent or 30.51 points at 1,589.94.

"The sharp decline in US shares on Friday is weighing on the Tokyo market," said Toshikazu Horiuchi, a broker at IwaiCosmo Securities.

"Trading is sluggish as investors are on the sidelines ahead of Britain's vote on Brexit," Horiuchi told AFP.

On Friday, major US stock indices slumped more than two percent to conclude a bruising week for markets rattled by the US-China trade clash.

The Dow Jones Industrial Average ended down 2.2 percent and the broad-based S&P 500 slumped 2.3 percent.

The declines followed hawkish comments from White House trade advisor Peter Navarro, who told CNN that US President Donald Trump would "simply raise" tariffs on $200 billion worth of Chinese goods if trade talks fail.

The dollar changed hands at 112.71 yen in early Asian trade, against 112.68 yen in New York late Friday.

Nissan was down 1.75 percent at 956.2 yen in early trade as ousted chairman Carlos Ghosn is expected to be charged and face new allegations for alleged financial misconduct later in the day.

Steelmakers slumped on concerns over a US-China trade war. Nippon Steel & Sumitomo Metal lost 1.58 percent to 1,954 yen with JFE Holdings down 1.92 percent at 1,888 yen.