Within two months of moving into the White House, Trump has already torn up the trans-Pacific free trade pact, threatened punitive tariffs against multinationals with factories outside the United States and attacked "currency manipulation" by export giant China.
US Treasury Secretary Steven Mnuchin makes his first official foreign foray when he joins the G20 gathering of finance ministers and central bankers from Friday in the western German spa town of Baden-Baden.
Germany adopted a conciliatory tone ahead of the meeting, shrugging off Trump's attacks against Berlin over its massive trade surplus.
"There is no reason to be pessimistic about the world economy, and there is no reason to be pessimistic about the relationship with the US," said a German finance ministry official.
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"There are topics that require discussion that are known to all, such as in the area of taxes. We think that these discussions will run constructively and lead to a good understanding," added the official, who spoke on condition of anonymity.
The issue is also expected to come up when Chancellor Angela Merkel meets Trump for the first time in Washington on Friday.
A European colleague was less ambivalent about his concerns, asking: "Will the US continue to believe in the G20?"
And IMF chief Christine Lagarde urged the G20 to "collectively avoid self-inflicted injuries".
"This requires steering clear of policies that would seriously undermine trade, migration, capital flows, and the sharing of technologies across borders," she wrote in a message that appeared targeted primarily at Trump.