Stock markets across the Asia-Pacific traded sharply lower on Monday as financial turmoil sparked by the US "reciprocal tariffs" escalated recession fears worldwide.

Hong Kong's Hang Seng Index dropped 2,445.19 points, or 10.7 percent, to end at 20,404.62 points in Monday's morning session. The retreat widened from 9.28 percent at opening.

This came on top of losses in Japan, where the benchmark Nikkei stock index shed 2,843.48 points, or 8.42 percent, in the first 15 minutes of trading, the lowest intraday level since October 2023.

"Japanese stocks are unlikely to stop declining unless US stocks cease falling further," said Yutaka Miura, senior technical analyst at Mizuho Securities Co.

The circuit breaker was triggered for Nikkei stock futures, temporarily halting trading due to the sharp fall.

South Korea's benchmark Korea Composite Stock Price Index (KOSPI) lost 103.57 points, or 4.2 percent, to 2,361.85 as of 11:20 am.

Due to the sharp decline, the bourse operator placed a sidecar order at 9:12 am, pausing program buying for five minutes, after the KOSPI 200 index fell more than 5 percent for over one minute.

It was the first sidecar order for program buying since August 2024, according to local reports.

The KOSPI plummeted as investors sold off stocks in response to increasing concerns about a recession after the US government revealed "reciprocal tariffs" last week, said analysts here.

Stocks in Singapore dipped over 7 percent at the start of Monday due to concerns about a global trade conflict following several countries mulling to respond to US tariffs.

The Straits Times Index plunged 7.37 percent, or 281.84 points, to 3,544.02 as Asian markets fell sharply.

Meanwhile, Indian shares declined at the beginning of trading on Monday, with the key Nifty index dropping over 3 percent.

The Nifty 50, representing the biggest Indian firms on the national stock exchange, was down 3.55 percent.

The Nifty IT, comprising India's leading information technology firms, which consider the United States their largest market, was down 5.53 percent.

Local media house The Times of India called Monday's loss a "bloodbath".

Australian blue-chip shares dived 6 percent when trading commenced on Monday, due to financial chaos triggered by the US tariffs in global markets.

A benchmark index of the nation's top 200 publicly traded firms dropped over 6 percent after the market opened, as the repercussions of the US tariffs continued to unsettle investors.

The Australian government was "preparing for further uncertain times", according to Prime Minister Anthony Albanese on Monday. "You can't change global events. What you can do is prepare for them," he told reporters.

On Wednesday, US President Donald Trump declared a 10 percent baseline tariff on imports from all trading partners and imposed higher rates on specific ones, with the decision provoking sharp criticism from economists, trade experts and foreign governments who view it as a misguided effort to utilize tariffs as a crude tool to tackle intricate trade disparities.