Oil prices plunged on Monday amid US President Donald Trump's new trade tariffs, while OPEC+ unveiled plans to ramp up production in May, which was followed by Saudi Arabia's move to cut next month's oil prices to Asia.

International benchmark Brent crude fell by around 3.8%, trading at $63.20 per barrel at 10.53 a.m. local time (0753GMT), down from $65.84 at the previous session's close. Brent declined to a four-year low.

US benchmark West Texas Intermediate fell about 0.8%, settling at $65.74 per barrel, compared to its prior session close of $66.33.

Prices fell sharply on the first trading day of the week as Trump reiterated his tough rhetoric on trade tariffs and the OPEC+ group announced plans to increase production in May.

China, the world's largest oil importer, responded with retaliatory measures against Trump's latest tariffs, while other major economies, including the EU, signaled similar actions, reigniting fears of a global trade war.

China has strongly reacted to US reciprocal tariffs, describing them as "America's hegemonic ambitions," claiming that they severely violate nations' legitimate rights and interests under World Trade Organization rules.

The US is "placing American interests above the common good of the international community and sacrificing the legitimate interests of all countries in service of America's hegemonic ambitions," said the Chinese Foreign Ministry in a statement.

Beijing announced a 34% additional tariff on all US imports on Friday in response to Washington's 34% reciprocal tariffs imposed on Wednesday.

Asian stock markets record significant losses

Early Monday, major Asian stock markets recorded significant losses, with Hong Kong's Hang Seng Index suffering the steepest decline, as escalating trade tensions between the US and China sparked investor concerns over a potential global recession.

The Asia Dow, which tracks leading blue-chip companies across the region, fell 9.25% to 3,636.19 points as of 0631GMT.

Japan's Nikkei 225 index declined 7.68%, closing at 31,187.50 points.

The Hang Seng Index, a key benchmark for Hong Kong's blue-chip stocks, plunged 12.46% to 20,002 points -- marking its worst single-day performance in 16 years.

China's Shanghai Stock Exchange dropped 8.48% to 3,058.74 points, while India’s Sensex index shed 3.76%, closing at 72,531.45.

OPEC+ to raise output

Meanwhile, eight OPEC+ members -- Saudi Arabia, Russia, Iraq, the UAE, Kuwait, Kazakhstan, Algeria, and Oman -- agreed on Thursday to accelerate their output increase plan, approving a 411,000 barrels per day hike in May, equal to three months' worth of scheduled increases.

Prices plunged further on Friday after China announced it would impose an additional 34% tariff on all US goods starting April 10.

In response to OPEC+'s accelerated production increase, Saudi Arabia, the world's top oil exporter, slashed May crude prices for Asian buyers to a four-month low. (AA)