A Japanese government report is warning that the trade policies of US President Donald Trump could trigger a series of tit-for-tat retaliatory measures, hurting the global trading system.
Every year, the trade ministry issues a report assessing the compliance of Japan's major trading partners with agreements.
This year, it mentions US tariffs imposed in March on steel and aluminum imports, as well as a recent US announcement on steep duties on Chinese products.
The ministry says the measures are based on a unilateral view held by Washington that its partners engage in unfair practices.
The report also points the finger at China.
It cites the non-transparent manner in which subsidies for certain industries are handed out.
Japan says it will deal with these and other problems in accordance with World Trade Organization rules.
But it's uncertain how effective such an approach will be.