TOKYO: Tokyo's key Nikkei index dropped three percent in morning trade Monday on concern over the war in Ukraine and as crude oil prices neared an all-time high.

The benchmark Nikkei 225 index tumbled 3.03 percent or 787.97 points to 25,197.50, while the broader Topix index fell 2.91 percent or 53.69 points to 1,791.25.

In New York, all three major indices finished the week with losses, with the broad-based S&P 500 ending down 0.8 percent.

The Dow Jones Industrial Average lost 0.5 percent, while the tech-rich Nasdaq Composite Index dropped 1.7 percent.

"Selling will be driven today by caution over the situation in Ukraine, following reports that the US administration is considering banning imports of Russian crude oil," Mizuho Securities said.

It came as Brent oil prices leapt to almost $140 per barrel, the highest since 2008 and nearing an all-time record.

On Saturday, card payment giants Visa and Mastercard said they would suspend operations in Russia, the latest major US firms to join the business freeze-out of Moscow.

Masayuki Kubota, chief strategist at Rakuten Securities, warned that countries imposing sanctions could see economic impacts as well.

"In particular, the damage to Europe, which has close economic ties with Russia, will be especially large," he noted.

The dollar fetched 115.01 yen, up from 114.69 yen in New York on Friday.

In Tokyo trading, Sony Group fell 0.70 percent to 11,305 yen after announcing a plan to team up with Honda to start a new company that will develop and sell electric vehicles. Honda lost 3.32 percent to 3,108 yen.

Nissan dived 6.51 percent to 463.7 yen while Toyota sank 5.47 percent to 1,860.5 yen.

Panasonic, which said it would stop exports to Russia citing logistical hurdles, dropped 4.89 percent to 1,058.5 yen.

But drugmaker Shionogi jumped 3.13 percent to 7,957 yen after a trial showed the Covid-19 vaccine it is developing was "not inferior" to Pfizer's vaccine when administered as a booster to people who received two mRNA vaccine doses.