The Trump administration’s trade policies are likely to hurt the US economy and undermine the world’s trade system, the IMF has warned.
IMF Director Christine Lagarde said a trade war would lead to “losers on both sides” and could have “serious” impact.
The caution came as the US prepares to levy new tariffs on $50bn worth of Chinese imports.
New duties on foreign steel and aluminium, announced in March, have already gone into effect.
Those tariffs have already prompted Europe, Mexico, Canada and China to introduce or announce plans for counter-measures in retaliation.