The dollar has slipped against the euro despite encouraging US data on housing and jobs, while the yen slumped to new multi-year lows on speculation of new easing.
The euro on Thursday benefited from more positive remarks from regional leaders and solid results of a Spanish bond auction, analysts said.
"The euro rallied to 1.3376 as the European Central Bank and European Union president Herman Van Rompuy stirred hopes of seeing the euro-area return to growth in 2013, but optimism surrounding the single currency may fail to materialise as the debt crisis continues to drag on the real economy," said David Song of DailyFX.
Also helping was strong investor enthusiasm at a $US4.5 billion ($A4.29 billion) Spanish bond auction, pushing the troubled government's borrowing costs lower.
At 2200 GMT (0900 AEDT Friday), the euro was at $US1.3375, compared with $US1.3286 late on Wednesday.
The dollar failed to get a boost from a strong fall in weekly jobless claims, a sign of the pace of layoffs, and a rebound in housing starts in December, showing sustained strength in the housing sector.
The yen meanwhile fell to a fresh 30-month low. The dollar topped the Y90 level briefly before slipping back to Y89.86, compared to Y88.37 a day earlier.
The euro rose to Y120.20, its best level since April 2011, up from Y117.42 on Wednesday.
David Gilmore of Foreign Exchange Analytics, said speculation was rising that the Bank of Japan could add to stimulus measures in its next policy meeting on January 21-22.
The British pound fell to $US1.5992 from $US1.6006, while the dollar gained to 0.9322 Swiss francs from 0.9309 francs.