China will slap port fees on US-owned, operated, built, or flagged vessels on Tuesday as a countermeasure to US port fees on China-linked ships starting the same day, China's transport ministry said on Friday.

Later in the day, US President Donald Trump said he was raising tariffs on Chinese exports to the US to 100% and imposing export controls on critical software in a reprisal to export limits by China on rare earth minerals.

There are relatively few US-built or US-flagged vessels conducting international trade, but China will ensnare more ships by applying levies to companies with 25% or more of their shares or board seats held by US-domiciled investment funds, analysts said.

"This casts a wide net and could affect many public shipping companies with a listing on US stock exchanges," said Erik Broekhuizen, a marine research and consulting manager at ship brokering firm Poten & Partners.

"The potential impact is significant."

On Tuesday, ships built in China - or operated or owned by Chinese entities - will also need to pay a fee at their first port of call in the United States.

Some vessels to pay fees to both China and US

US-based shipping company Matson told customers it is subject to the new China port fees and has no plans to change its service schedule.

Also likely affected are CMA-CGM's US-based American President Lines and Israel-based Zim, which appears to have more than 25% of its shares owned by US entities, Lars Jensen, CEO of container shipping-focused consultancy Vespucci Maritime, said on LinkedIn.

The fees in both China and the US will apply to 100 vessels owned by Poseidon's Seaspan and chartered by container lines, said Jensen.

Maersk Line Limited, APL, Zim and Seaspan did not immediately respond to requests for comment on the fees.

Oil tanker operators are mostly based outside the United States, but they may get stung by China's port fees because they are listed in the US, analysts said.

For example, Scorpio Tankers STNG.N has the industry's largest and youngest fleet and is US-listed. It did not immediately respond to a request for comment.

The Chinese port fees "have thrown the tanker market in turmoil," Broekhuizen said in a client note, adding that many vessels that could be affected are already on their way to China.

An analysis by Vortexa showed 43 liquefied petroleum gas-carrying super tankers, or 10% of the global fleet, will be affected by China's port fees, said Samantha Hartke, who heads Americas analysis for the energy research firm.

Vessels owned or operated by a Chinese entity will face a flat fee of $50 per net tonnage per voyage to the US. China-owned carrier COSCO 601919.SS, including its OOCL fleet, is the most exposed with fees of around $2 billion in 2026, analysts said. COSCO did not immediately comment.

China calls US fees discriminatory

The US fees on China-linked vessels, following a probe by the US Trade Representative, are part of a broader US effort to revive domestic shipbuilding and blunt China's naval and commercial shipping power.

"It is clearly discriminatory and severely damages the legitimate interests of China's shipping industry, seriously disrupts the stability of the global supply chain, and seriously undermines the international economic and trade order," the Chinese ministry said.

The USTR's office did not respond to a request for comment.

Over the past two decades, China has catapulted itself to the No. 1 position in the shipbuilding world, with its biggest shipyards handling both commercial and military projects.

The fees announced by China, like those put in place by the US, "add further complexity and cost to the global network that keeps goods moving and economies connected, and risk harming their exporters, producers, and consumers at a time when global trade is already under pressure," said Joe Kramek, president and CEO of the World Shipping Association.

Rates rise for three years

For US-linked vessels berthing at Chinese ports starting Tuesday, the rate will be 400 yuan ($56.13) per net metric ton, the Chinese transport ministry said.

That will increase to 640 yuan ($89.81) from April 17, 2026, and to 880 yuan ($123.52) from April 17, 2027.

For vessels calling at Chinese ports from April 17, 2028, the charge will be 1,120 yuan ($157.16) per net metric ton.

Tensions between China and the United States have deepened since September, with the two superpowers struggling to move beyond their trade tariff truce - a 90-day pause from August 11 that ends around November 9.

Retaliatory tariffs in the US-China trade war this year have sharply curtailed Chinese imports of US agriculture and energy products.