United States President Joe Biden and President Xi Jinping of China will meet on Saturday in what is expected to be their last face-to-face meeting during Biden’s term as Beijing braces for a Donald Trump presidency in Washington.

The two leaders are attending a two-day heads of state meeting of the Asia Pacific Economic Cooperation group in Lima, Peru, that began on Friday. Saturday’s meeting will be the third time the two will meet in person since Biden took office.

Relations between China and the US, the world’s most important superpowers, had nosedived during Trump’s first term as president, when he started a trade war with Beijing, using punishing tariff rates.

Yet ties became even rockier in the past four years of the Biden administration, with sore points ranging from trade wars to TikTok. In 2023, Mexico overtook China as the US’s biggest trade partner for the first time in 20 years as economic ties deteriorated.

Still, Biden has sought to maintain a steady relationship with Beijing. US National Security Adviser Jake Sullivan told reporters ahead of the Lima meeting that Xi and Biden would discuss the transition to a Trump White House and the need for level-headedness on both sides in that period.

In his election campaign this year, Trump threatened to slap 60 percent blanket tariffs on all Chinese imports to the US.

Here’s a picture of how the US-China relations soured under Biden – and what to expect under Trump 2.0:

Trade wars

Trump, in his first run as government, kickstarted a trade war with China after his administration blamed Beijing for ‘unfair’ trade practices that it said contributed to a large trade deficit in China’s favour. Those practices, the US maintains, include forced labour, intellectual property theft and unfairly low pricing that hurts US producers. China has long denied these allegations.

From January 2018, the Trump administration imposed higher tariffs on Chinese imports at rates of between 10 to 25 percent under Section 301 of the Trade Act. Beijing accused Washington of ‘nationalist protectionism’ and retaliated with higher tariffs on US imports.

However, close to the end of Trump’s first term, the two countries agreed to a deal that would see Washington reduce tariffs on some goods. China in return committed to improving intellectual property rights and also buying an additional $200bn-worth of US goods above 2017 levels by the end of 2021. Trump touted the deal with Xi, his “very good friend” as a success, but researchers in 2022 said that China had bought goods worth only 58 percent of the amount it had committed to purchasing.

Biden mainly kept Trump-era tariffs in place throughout his term and additionally sanctioned Chinese companies for dealing with Russia, following Russia’s invasion of Ukraine.

In May 2024, the Biden administration reviewed the Section 301 restrictions and imposed higher rates of between 25 to 100 percent on some Chinese imports. Electric vehicles and solar cells were among the affected goods.

President Biden also tightened export controls on semiconductor technology important for developing artificial intelligence and threatened to expand sanctions on Chinese banks working with Russia. Tariffs on China currently account for $77bn of the $79bn that the US government earns through tariffs, according to the Tax Foundation, a Washington-based monitor. By 2022, the US trade deficit with China stood at $383bn.

On protecting Taiwan

Face-offs between the two countries over self-ruled Taiwan intensified under Biden. While China claims the region as its territory, the US is Taiwan’s strongest ally and backs the island to counter Beijing’s growing military power in the Asia Pacific.

Beijing does not rule out using force to subdue Taiwan. Routinely, the Chinese military conducts drills with warships and aircraft near Taiwan, prompting alarm. In the past two years, those drills have intensified, especially in the wake of top US officials like then-Speaker Nancy Pelosi visiting Taipei in 2022.

In its latest move, China launched the Joint Sword-2024B exercises on October 14. Beijing said the military drills were a “stern warning to the separatist acts of ‘Taiwan Independence’ forces”.

“We can see that the world has a lot of regional flashpoints that are ongoing and maybe Beijing sees this as … an opportunity to test their will and see if the world’s support for Taiwan is strong enough,” Kuang-shun Yang, the co-founder of the Taipei-based think tank US-Taiwan Watch, told Al Jazeera, referring to the Russia-Ukraine war, and the conflicts in the Middle East.

It is widely believed that a Chinese invasion could prompt a US military response, although Washington’s “strategic ambiguity” policy keeps both sides guessing. Taiwan’s President William Lai Ching-te though, has promised to “resist annexation or encroachment” by Beijing.

The US is Taiwan’s main supplier of weapons. In late October this year, the US angered Beijing when it approved a $2bn arms sale package to Taiwan, including advanced surface-to-air missile systems and radars. China pledged to take “all necessary means” to assert its ownership over the disputed region.

Tensions earlier flared directly between Washington and Beijing in February 2023 when Biden ordered the shooting down of a Chinese “spy” balloon allegedly equipped with antennas that traversed US airspace.

TikTok over in the US?

In April, Biden signed a law giving ByteDance – the Chinese owner of the wildly popular TikTok app – nine months to divest its stake in the company or face a ban in the US for allegedly endangering national security. The deadline for the sale – January 19 – is one day before Trump’s inauguration on January 20.

Successive US administrations, including Trump’s first government, have treated the app with distrust. Authorities cite growing concerns that data from TikTok’s 170 million US users could be tapped by China for espionage. Some intelligence officers of the Federal Bureau of Intelligence have even warned that Beijing could influence American users by manipulating TikTok’s highly effective algorithm that curates video content that users are exposed to.

TikTok denies those claims. Chief executive Shou Zi Chew, who was grilled by US lawmakers in Congress in March 2023, maintained that “Bytedance is not an agent of China”. The app is now banned from government-issued phones in the US, the United Kingdom and Canada.

Trump’s administration was the first to attempt a TikTok ban back in 2020, under an executive order. However, the company was able to secure an injunction from a Washington judge who said such a prohibition was unlawful. Experts say TikTok could again seek an injunction, and that the legal process could take several years.

China has maintained it is against the app’s sale.

What to expect under Trump?

Trump’s second term could see the trade war escalate, economists predict. His top cabinet picks include several officials known to advocate a tougher stance towards Beijing, including Florida Senator Marco Rubio. The senator, whom Trump has named as his incoming secretary of state, is under Beijing’s sanctions for his outspoken criticism of Chinese policies.

On the other hand, Trump’s cabinet also includes X and Tesla owner Elon Musk, who has – at least while wearing his businessman’s hat – been less hawkish towards China.

While the president-elect has long claimed that the US-China trade imbalance can only be corrected by slapping heavy tariffs on Chinese goods, analysts note that his first-term tariffs did not close the gap.

The tariffs, which were also meant to prompt US manufacturers in China to return to the country and increase production, actually caused some to shift to similarly cheap countries like Bangladesh or Vietnam instead, according to 2021 findings by QIMA, a Hong Kong auditing firm.

Meanwhile, Trump’s plans for Taiwan are less clear. In his first term, he spoke directly to former Taiwanese President Tsai Ing-wen, igniting Beijing’s anger. Traditionally, the US avoids leader-to-leader contact. Trump’s administration also increased weapon sales to the island.

However, during this year’s election campaign, Trump, while speaking on the Joe Rogan podcast, alleged that Taiwan stole American chip businesses, referencing the US’s reliance on the island’s semiconductors. He also criticised Taiwan for not paying the US for “protection”. Analysts say those comments could signal less friendly relations.

As for TikTok, Trump could prove more flexible, although he first led the charge against the company. During campaigns this year, he pledged to “save TikTok” – but has not revealed details. Trump argues banning TikTok would empower Facebook, which he calls an “enemy of the people.”

Experts say Trump could push for US authorities to modify the Biden ban or drop it. Tech regulation expert Anupam Chander told Al Jazeera that Trump could also ask the US Congress to empower him to re-negotiate with the company.

“I think many politicians would prefer that TikTok not go dark in the US in January. After all, some 170 million Americans continue to use the app, even after the government told them it’s a national security threat,” Chander said.