So far, the euro has shouldered much of the three-year fall in the U.S. currency, gaining about 50 percent against the dollar since early 2002. In the same period, the yen has gained only about half of that.
The euro's strength is causing concern throughout Europe about losses in export competitiveness. ECB President Jean-Claude Trichet and Chief Economist Otmar Issing both called last week for Asian countries to adopt more flexible exchange rates.
Many traders interpret such comments as asking China, which pegs its currency against the dollar, to allow its currency to rise.
Any revaluation of the Chinese currency would likely buoy other Asian currencies given the strong economist ties in the region.
"People want to buy Asia ahead of the G7 in case China does anything or there is a change of language," said Ian Gunner, head of foreign exchange research at Mellon Bank in London. "And if you want to buy Asia, the yen is a liquid vehicle."
Issing is due to speak again on Wednesday, and analysts said his comments would be closely watched, as would those of a series of U.S. Federal Reserve officials including Gary Stern, Ben Bernanke and Janet Yellen, who will also speak to the press this week.
Meanwhile, capital flow figures from the U.S. due on Tuesday were likely to put worries about the U.S. current account deficit back in the spotlight.
Much of the dollar's decline had been driven by worries that th U.S. may struggle to finance its growing current account deficit with capital from overseas. The U.S. trade deficit hit a record $60.3 billion in November.