The US and China have escalated their ongoing trade war by implementing 25% tariffs on $16bn worth of imports on both sides, bringing the amount levied to a combined $100bn (£78bn) since July.

Beijing began implementing the new tariffs on Thursday, when the US said it would begin collecting extra duties in retaliation for what it claimed were unfair Chinese trade practices.

“China firmly opposes [the US tariffs] and has to continue to make necessary counterattacks,” China’s ministry of commerce said in a statement.

The latest round of tariffs comes as Chinese and US officials are due to meet in Washington for talks that few expect will bring an end to months of tit-for-tat threats and tariffs.

On Monday, Donald Trump told Reuters he did not “anticipate much” from the negotiations in Washington. The US president said any resolution would “take time because China’s done too well for too long, and they’ve become spoiled”.

The White House claims China steals foreign companies’ intellectual property or forces them to give it up, and that industrial subsidy programmes unfairly benefit Chinese businesses. The latest round of US tariffs target electronics, plastics, chemicals, semiconductors and other goods from the “Made in China” industrial plan to upgrade Chinese manufacturing capabilities.

The US trade representative’s office is holding public hearings this week on a proposal for more tariffs of up to 20% on an additional $200bn in Chinese goods. The US has threatened tariffs on all $500bn worth of Chinese exports to the US, an amount Beijing cannot reciprocate. US exports to China last year were worth about $130bn.

China’s levies have been aimed at agricultural products such as soybeans, a top US export to China. Its new tariffs target various types of vehicles from vans to tractors and off-road vehicles, as well as textiles, bicycles, engines, golf carts, and hospital equipment.

China has accused the US of threatening free trade and on Thursday promised to file a new complaint at the World Trade Organization.

“To safeguard free trade and multilateral systems, and defend its own lawful interests, China will file a suit regarding these tariff measures under the WTO dispute resolution mechanism,” it said.

With the Chinese economy slowing, authorities have instructed Chinese media to scale back direct attacks on Trump and references to the trade war in connection with the economy.

An editorial in the state-run tabloid Global Times on Thursday criticised the US for “breaking agreements and creating trade conflict” but placed the US-China trade war in the broader context of US disputes with the EU, Canada, and Mexico. “The US is moving further towards unilateralism,” the paper said.