US President Donald Trump. Picture: Reuters

Beijing - The United States and China on Thursday enacted tariffs on 16 billion dollars' worth of imports each, as the trade war between the world's largest economies escalates.

The 25-per-cent US duties affect Chinese goods ranging from drainage pipes to agricultural products and railway wagons. China's retaliatory tariffs apply to US goods including coal, petrol, vehicles, motorcycles and medical equipment.

China had to "continue to make the necessary counterattacks," the Chinese Commerce Ministry said in a statement immediately after the tariffs began around midnight on the US East Coast (0400 GMT).

China will file a complaint with the World Trade Organization, the statement added.

This is the second salvo in the countries' trade war, after last month Washington imposed tariffs on 34 billion dollars' worth of Chinese goods, with Beijing retaliating with duties on the same amount of US products.

A Chinese trade delegation arrived in Washington this week for negotiations aimed at defusing the tensions.

The US accuses China of unfair trading practices, particularly on technology. US President Donald Trump also wants to slash the countries' trade deficit, which reached 375 billion dollars last year.

Trump has threatened to impose tariffs on a total of 550 billion dollars' worth of Chinese goods. This exceeds the totality of Chinese exports to the US last year, which was 505 billion dollars.

Beijing is somewhat limited in the extent to which it can hit back, as it exports more to the US than it imports from the world's largest economy.

Nevertheless, major US companies such as Apple, Starbucks and Nike, could be hit by Chinese consumer boycotts.

China's economy, which is expected to grow around 6.5 per cent this year, has not so far been seriously affected by the tensions.

In particular, US-China bilateral trade showed strong year-on-year growth in July.

Nevertheless, the yuan currency has plunged in recent months, and businesses' confidence is being affected, experts say.

"If the trade war can end as soon as possible, I think the impact on the Chinese economy will be relatively small," said independent economic commentator Hu Xingdou. "But if the trade war continues to escalate, from 50 billion to 200 billion to 500 billion, then the blow to China's confidence will indeed be relatively large."

An all-out trade war could shave off 0.25 per cent of the GDP of both economies this year, with more damage expected in 2019, according to research by Singapore's DBS Bank.