The dollar firmed on Monday as fresh threats of tariffs from U.S. President Donald Trump dented risk sentiment, casting a shadow over commodities markets and putting pressure on the euro and the Australian and Canadian dollars.

The dollar firmed on Monday after U.S. President Donald Trump announced plans to impose new 25% tariffs on all steel and aluminum imports, pressuring the euro and commodity-linked currencies like the Australian and New Zealand dollars.

European Union trade ministers will hold an unscheduled video conference on Wednesday to discuss the bloc's response to impending U.S. steel and aluminium tariffs, EU diplomats said on Tuesday. U.S. President Donald Trump signed proclamations late on Monday to raise tariffs on all steel and aluminium imports to 25% without exceptions or exemptions.