U.S. trading partners were bracing Tuesday for an expected fresh raft of Donald Trump tariffs, while the U.S. president promised to be "very kind" in addressing what he says are unfair trade imbalances.

Trump — who has been making unprecedented use of presidential powers since taking office in January — said he could announce as early as Tuesday night exactly what "reciprocal tariffs" will be imposed.

The Republican billionaire insists that action is needed because the world's biggest economy has been "ripped off by every country in the world," and is promising "Liberation Day" for the United States.