Mainland Chinese shares declined on Monday amid uncertainty on the U.S.-China trade front, after tariffs on Chinese goods were raised last Friday.

The Shanghai composite tumbled 1.21% to close at 2,903.71 and the Shenzhen component fell 1.43% to finish its trading day at 9,103.36. The Shenzhen composite slipped 1.076% to close at 1,551.75. They had soared last Friday despite the U.S. raising tariffs from 10% to 25% on $200 billion worth of Chinese goods.

Other major Asian markets also fell.

The Nikkei 225 in Japan declined 0.72% to close at 21,191.28, with shares of index heavyweight Softbank Group falling 3.25%. The Topix index also slipped 0.53% to finish its trading day at 1,541.14.

In South Korea, the Kospi fell 1.38% to close at 2,079.01, while Australia's shed 0.21% to finish its trading day Down Under at 6,297.60.

"Lack of activity data and public holidays in some countries will make it a slow start of the week for Asian markets. But the risk-off continues with the escalation of US-China trade war after last Friday's move by the US to raise tariffs on Chinese goods. All eyes are on China's retaliation.," Prakash Sakpal, Asia economist at Dutch bank ING, wrote in a note.

Markets in Hong Kong were closed on Monday for a holiday.

Futures also pointed to significant declines on Wall Street when they open later on Monday stateside. As of 12:10 a.m. ET Monday, the Dow Jones Industrial Average was poised to see an opening decline of more than 200 points.