The International Monetary Fund (IMF) has warned that the Trump administration's trade policies are likely to hurt the US economy and undermine the world's trade system.
The organisation outlined the risks in its annual review of the US economy.
The caution comes as the US prepares to levy new tariffs on $50 billion worth of Chinese imports.
New duties on foreign steel and aluminium, announced in March, have already gone into effect.
The IMF said the White House, which has also threatened to withdraw from the North American Free Trade Agreement (NAFTA), is responding to rising concerns about the side-effects of free trade.