Taking aim at what he said was a surge of illegal immigrants across the southern border, Trump vowed on Thursday to impose a tariff on all goods coming from Mexico, starting at 5% and ratcheting higher until the flow of people ceases.
The Mexican peso tumbled against the greenback, losing as much as 3.4% at one point, for its steepest single-day loss since October. It was down 2.65% at 19.6485 per dollar.
Trump's surprise duties on Mexican imports "spurred sharp losses in the Mexican peso and a general risk-off move that strengthened the yen," said Marc Chandler, chief market strategist at Bannockburn Global Forex LLC.
Several different currencies have served as safe havens during the global trade conflict, but the yen has consistently been among the strongest this year, and on Friday investors appeared to opt for the Japanese currency.
The yen increased 1.11% at 108.41 per dollar and 0.75% per euro.
For May, the Japanese currency was on track to gain 2.72% against the dollar and 3.15% versus the euro.
The Swiss franc also enticed safe-haven buying, rising 0.69% at $1.0008, near its strongest versus the dollar since April 10.
(Graphic: Japanese yen surges link:
The impact of escalating trade tensions between Washington and Beijing is starting to show up in economic data, with a key measure of Chinese manufacturing activity disappointing investors, and Trump's latest salvo fueled a rush on Friday to safe-haven assets such as government bonds and the yen.
The U.S. dollar has itself served as a safe haven currency in recent times, but on Friday, it fell 0.34% against a basket of other currencies , hovering below a two-year peak reached last week.
For the month, the dollar index was on track for a 0.4% gain, extending its winning monthly streak to four.
"The U.S. dollar may be embarking on a major turning point," said Jack McIntyre, portfolio manager at Brandywine Global.
The dollar's broad losses on Friday were compounded by comments from senior policymakers, with the U.S. Federal Reserve Vice Chair Richard Clarida on Thursday discussing the possibility of rate cuts should the world's biggest economy take a turn for the worse, though he also said he thought the U.S. economy is in "a very good place".
U.S. interest rates futures implied traders expect at least one rate cut from the Federal Reserve by year-end.
Government data on Friday showed a modest pickup in inflation in April, while a private report indicated a stronger-than-forecast improvement in U.S. Midwest manufacturing activity in May.
(GRAPHIC-Rising trade tension on U.S. rate-cut expectations link:
(Additional reporting by Abhinav Ramnarayan in LONDON; Editing by David Holmes, Stephen Powell and Tom Brown)
By Richard Leong
