The euro rallied broadly on Friday on growing optimism the region's debt crisis has turned the corner, while the yen was headed for its 11th consecutive week of losses against the dollar.
The euro zone common currency hit an 11-month high versus the dollar and a 21-month peak versus the yen after the European Central Bank said banks will repay a greater-than-expected 137 billion euros in loans next week, a sign that at least parts of the financial system are on the mend.
"For now, the trade of 'buy euro, sell yen' seems to be in play," said Win Thin, senior currency strategist at Brown Brothers Harriman in New York.
The euro climbed 0.6 percent to $1.3453, after rising to $1.3479, its highest level since late last February. For the week, it gained about 1.2 percent.
A survey showing improvement in business confidence in Germany underpinned the euro strength.
Camilla Sutton, chief currency strategist at Scotiabank in Toronto said the euro is rapidly approaching three major resistance levels. She cited this year's high of $1.3486, the 50 percent retracement from the high in May 2011 to the low in July 2012 at $1.3492, and the psychologically important $1.3500 figure, all of which are within reach.
But Sutton cautioned, "We would not position too early for the downside and would instead trade with the trend until it breaks."
The ECB is the first major central bank to start moving away from unconventional monetary policy measures, unlike the U.S. Federal Reserve and Bank of Japan, which are buying bonds to stimulate growth.
When a central banks purchases assets, effectively expanding its balance sheet, the country's currency tends to be hurt because it increases the currency's supply.
Reflecting a dramatic improvement in the euro zone's funding conditions, the cross currency basis swap, or the relative premium for swapping euro Libor for dollar Libor, on Friday traded at -17.5 basis points on three-month contracts , the lowest premium in 20 months.
A lower swap premium suggests smaller demand for the greenback and diminished funding stress in the euro zone.
Two-year German bond yields jumped to their highest since March 2012 and rose above their U.S. counterparts for the first time in two years, suggesting interest-rate differential is moving in favor of the euro, analysts said.
In the options market, traders reported demand for euro calls, which are bets on more gains, although one-month risk reversals on Friday still showed a minor bias for puts or more euro weakness. However, this was the smallest euro put level since November 2009.
The dollar rose as high as 91.19 yen, the strongest since June, 2010, rising past reported options barrier at 90.75 and 91 yen. It was last up 0.6 percent at 90.88 yen.
On the week, the dollar rose about 1 percent versus the yen, and has gained every week versus the yen since the week ended Nov. 11.
Expectations that Japan's new prime minister, Shinzo Abe, will force the central bank to aggressively ease monetary policy has caused the yen to lose more than 10 percent of its value against the dollar since mid-November, and many expect more declines.
Japan's core consumer prices slipped for a second straight month in the year to December, signaling the economy was still in deflation and piling more pressure on the central bank to adopt more stimulus steps to achieve its new inflation target.
The yen's steep drop has raised eyebrows abroad, with German Chancellor Angela Merkel singling out Japan on Thursday as a source of worry. But Japanese Finance Minister Taro Aso said Friday that monetary easing was aimed at pulling the country out of deflation, not manipulating currencies.
(Read More: Germany's Central Bank Head Slams Japan's Yen Policy)
BNP Paribas in a note said the yen's downside momentum remained strong, but the back-and-forth statements about the currency's weakness between foreign politicians and Japanese officials should exacerbate volatility.
The euro rose 1.3 percent to 122.40 yen putting it on track for a weekly rise of 2 percent, the seventh straight week of gains. It had earlier touched 122.77, its highest level since mid-April 2011.