The dollar dipped for the fourth day running against the basket of currencies used to measure its broader strength on Monday, as reaction to a G20 summit dominated by the Trump administration's protectionist bent extended last week's sales.
The greenback has been on the retreat since the U.S. Federal Reserve raised interest rates on Wednesday but stopped short of predicting a sharper acceleration in monetary tightening over the next two years.
For currency markets, the meetings of Group of 20 financial leaders added up to a renewed expression of concern about the United States' global trade relations and by implication the Trump White House's concern over the strong dollar.
The post-meeting communique retained language on avoiding currency manipulation which has previously seemed aimed chiefly at Japan and China, but it omitted a call for free trade seen as opening the door to more overt efforts by Washington to shift the balance of its international relationships.
"If they are going to push on trade, then you have to expect that the U.S. will want to talk to its major trade partners about where it feels there is unfairness in the relationships," said Simon Derrick, head of global market research with Bank of New York Mellon in London.
"None of us knows, but it gives me a hint that if there is a belief in the U.S. that some nations have manipulated their currencies then they will be looking at ways of addressing that (and) that would be aiming at a weaker dollar."
The dollar index fell by as much as 0.3 percent in Asian and early European trading before recovering some ground to stand just 0.1 percent weaker on the day at 100.25.
It was marginally higher at 112.86 yen and 0.2 percent weaker against the euro at $1.0755.
The logic so far on the Trump administration's protectionist leanings on trade are that, by imposing a new round of tariffs and taxation on imports, it would broadly support the dollar.
But a number of U.S. banks are now openly expressing doubts about how fast any border tax reform will come into being, or whether it will ever pass Congress at all in a form that would have a significant impact on pricing and the dollar.
Citi was the latest major lender to abandon its headline forecast for a fall in the euro to below parity with the dollar, citing both disappointment over the Fed and signs Trump's fiscal and tax plans may be delayed while he deals with healthcare.
In a note sent to clients late on Friday, analysts from the world's biggest currency trader upped its prediction for the single currency over the next six to 12 months to $1.04 from $0.98 previously.
The note also said the bank's base case was a defeat of Marine Le Pen in French elections in May that would remove a discount for political risk from the euro in the short term.
"(That is) one factor in our $1.10 forecast (for three months' time)," the bank said. "In addition, markets are getting a sense that the European Central Bank may be moving slowly to a less accommodative monetary stance."
For Reuters Live Markets blog on European and UK stock markets see reuters://realtime/verb=Open/url=http://emea1.apps.cp.extranet.thomsonreuters.biz/cms/?pageId=livemarkets (Editing by Andrew Heavens/Ruth Pitchford)