The dollar fell to a nearly four-week low against the yen on Monday as softer-than-expected U.S. manufacturing data suggested the economy may have run out of steam at the end of the first quarter, interrupting a recent run of generally upbeat data.

The euro, meanwhile, fell to a more than one-month trough versus the yen as investors favored the safe-haven Japanese currency following unexpectedly weak Chinese factory activity and renewed uncertainty in the Korean peninsula.