(BSS/AFP) - The United States unveiled new port fees on Chinese built and operated ships Thursday, in a bid to boost the domestic shipbuilding industry and curb China`s dominance in the sector.

The move -- which stems from a probe launched under the prior administration -- comes as the United States and China are locked in a major trade war over President Donald Trump`s tariffs and could further ratchet up tensions.

"Ships and shipping are vital to American economic security and the free flow of commerce," US Trade Representative Jamieson Greer said in a statement announcing the new fees, most of which will begin in mid-October.

Under the new rule, per tonnage or per container fees will apply to each Chinese-linked ship`s US voyage, and not at each port as some in the industry had worried.

The fee will be assessed only up to five times per year, and can be waived if the owner places an order for a US built vessel.

Dominant after the Second World War, the US shipbuilding industry has gradually declined and now accounts for just 0.1 percent of global output.

The sector is now dominated by Asia, with China building nearly half of all ships launched, ahead of South Korea and Japan.

The three Asian countries account for more than 95 percent of civil shipbuilding, according to UN figures.

There will be separate fees for Chinese operated ships and Chinese built ships, and both will gradually increase over subsequent years.

For Chinese built ships, the fee starts at $18 per NT or $120 per container -- meaning a ship with 15,000 containers could see a whopping fee of $1.8 million.

Beijing warned on Friday the new fees would be "detrimental to all parties."

"They drive up global shipping costs, disrupt the stability of global production and supply chains, increase inflationary pressure within the United States, and harm the interests of American consumers and businesses," foreign ministry spokesman Lin Jian said.

"Ultimately, they will not succeed in revitalizing the US shipbuilding industry," he said.

US groups representing some thirty industries had voiced their concerns in March about the risks such fees could have on the prices of imported products.

One business surveyed by the groups expressed worry that proposed fees, alongside tariffs on China and other countries, as well as duties on steel and aluminum imports, would put "extraordinary pressure on US retailers."

All non-US built car carrier vessels will also be hit with a fee beginning in 180 days.

Washington is also introducing new fees for liquified natural gas (LNG) carriers, though those do not take effect for three years.

A fact sheet accompanying the announcement said fees will not cover "Great Lakes or Caribbean shipping, shipping to and from US territories, or bulk commodity exports on ships that arrive in the United States empty."

In addition to the fees, Greer announced proposed tariffs on some ship-to-shore cranes and on Chinese cargo handling equipment.

"The Trump administration`s actions will begin to reverse Chinese dominance, address threats to the US supply chain, and send a demand signal for US-built ships," Greer said.