The US launched a probe to consider slapping almost 100 per cent tariffs on imported steel pipes from China in a move that could widen a trade spat between the two key powers. Washington has decided to “initiate anti-dumping and countervailing duty investigations on imports” of Chinese “seamless” pipes used to convey water, steam, chemicals, oil products and natural gas, the commerce department said. The pipes were allegedly backed by unfair subsidies.

Dumping occurs when a foreign company sells a product in the U S at less than normal value. Subsidies are financial assistance from foreign governments that benefit the production, manufacture, or exportation of goods. The commerce department’s action came less than a month after president Obama imposed punitive duties on Chinese-made tires, igniting the first trade spat of his presidency.

An angry Beijing lodged a complaint at the World Trade Organisation and retaliated by launching a probe into possible unfair trade practices involving imports of US car products and chicken meat. Beijing charged that Washington’s move violated WTO rules but Obama denied that it amounted to protectionism. Just last week, the New York Times reported that Washington had imposed tariffs on imports of solar panels, which had become “too sophisticated” to qualify for duty-free import.