Trump threatens 50% tariffs on China as report suggests plans for arms shipment to Iran

U.S. President Donald Trump on Sunday threatened to impose a 50% tariff on China, after a report emerged that Beijing was preparing to deliver a shipment of new air defense systems to Iran.

"I hear news reports about China giving [Iran] the shoulder missiles... what's called the shoulder missile, anti-aircraft missile. I doubt they would do that... but if we catch them doing that, they get a 50% tariff, which is a staggering — that's a staggering amount," Trump said, in response to a question on whether a previous threat of tariffs on countries found supplying military equipment to Iran would also apply to China.

Trump's comments, made in a televised phone call with Fox News, came as CNN, citing insiders, reported on the same day that U.S. intelligence assessments suggested an impending Chinese shipment of man-portable air defense systems (MANPADS) — a shoulder-operated, surface-to-air missile platform — to Iran.

In his interview with Fox News, however, Trump stopped short of confirming the credibility of the underlying coverage, saying that such reports "[don't] mean much to me, because they're still fake."

Speculation has mounted over China's role in Iran's war efforts.

In the hours following last week's temporary ceasefire between the U.S. and Iran, the New York Times, citing three Iranian insiders, reported that China "pressed" Iran toward a ceasefire deal.

In response, China's Foreign Ministry spokesperson Mao Ning told a reporter at an April 8 press conference that China had been "making active efforts to promote peace talks and end hostilities," but did not confirm an official mediation role.

China, one of Iran's closest allies, has up until recently been "fairly reticent" in its support to Tehran, said Dylan Loh, associate professor in public policy and global affairs at Singapore's Nanyang Technological University.

"China seems to be selectively wielding its influence and, as seen in the latest developments, [is] willing to engage in a more proactive way when it senses an opportunity to make an impact," Loh added.

While China has been one of Iran's most vocal sources of support, there have been no official accounts of Beijing providing Tehran with military or financial backing since the start of hostilities on Feb. 28.

If confirmed, China's delivery of weapons to Iran would "mark a departure" in Beijing's response to the situation in the Middle East, Loh said, adding it would "inject greater uncertainty" into the overall situation, even as the weapons themselves might not play a decisive role in Iran's retaliatory efforts.

Analysts have previously suggested to CNBC that China's support for Iran is likely motivated by Beijing's own material and economic interests, rather than a meaningful shift in foreign policy.

Zongyuan Zoe Liu, a senior fellow for China Studies at the Council on Foreign Relations, told CNBC last Friday that Beijing's economy remained fundamentally reliant on seaborne exports, and would therefore be vulnerable to an economic downturn resulting from a prolonged closure of the Strait of Hormuz.

In 2025, Beijing reportedly purchased more than 80% of Iran's heavily sanctioned oil exports, meeting more than 10% of China's total demand, according to estimates from maritime intelligence firm Kpler.

As one of Iran's key economic partners, Chinese-flagged oil tankers in the Persian Gulf have reportedly been among the few vessels that have been allowed passage through the Strait of Hormuz since the start of hostilities.

Yet, since Tehran's closure of the Strait of Hormuz, gasoline prices in China have still risen by roughly 11%, according to figures from China's National Development and Reform Commission, triggering a cap on further fuel price hikes as authorities look to shield consumers from further fallout from the war.

Just as China's reported weapons shipment to Iran remains unverified, President Trump's intentions to follow through on his threats of tariffs on China are similarly unclear.

Since the start of the U.S.-Israel war in Iran, Trump has vacillated between threats to wipe out Iran's populace and offers of diplomatic off-ramps, in what critics have often labeled his "TACO" (Trump Always Chickens Out) tendencies.

In an incendiary Easter Sunday post on his Truth Social account, Trump threatened to bomb critical Iranian infrastructure, including bridges and power plants, if Tehran did not reopen the Strait of Hormuz.

This was followed by another Truth Social post where Trump said that "a whole civilization will die tonight," if the Hormuz Strait was not opened ahead of an April 8 deadline — a threat which did not materialize.

Still, Loh stressed that Trump has also demonstrated a willingness to follow through on his warnings.

"Venezuela, Iran, the global tariffs and so forth are instructive examples. I think if [Trump] has solid evidence that China is prepared to help Iran in a substantial manner, he will respond," Loh said.

Trump on Sunday announced a complete blockade on vessels exiting the Strait of Hormuz, after peace talks between Iran and the U.S. fell through, with Iranian state media citing "unreasonable demands" from the U.S. delegation led by Vice President JD Vance.

President Trump is slated to meet with Chinese President Xi Jinping in a summit in Beijing on May 14 and 15.

China's embassy in Singapore has not responded to CNBC's requests for comment.

— CNBC's Evelyn Cheng contributed to this report.