The euro retreated to $1.3889 in Tokyo afternoon trade from 1.3905 in New York late Tuesday. The single European currency rose to 115.07 yen from 114.91 yen.
The dollar firmed to 82.85 yen from 82.64 yen.
"The dollar drew buybacks after suffering broad-based selling earlier on the view that rising crude oil prices would be negative to the US economy," said Teppei Ino, analyst at the Bank of Tokyo-Mitsubishi UFJ.
Saudi Arabia's assurances Tuesday that it would counter any disruptions of the global oil market pushed crude prices down Tuesday, giving a boost to the US stock market.
New York's main contract, light sweet crude for April delivery, fell below $105 per barrel in Asia Wednesday.
After moving from $1.37 to $1.40 last week, the European common currency hit a four-month high of $1.4037 Monday amid expectations of a rate hike by the European Central Bank as early as April.
But eurozone debt worries resurfaced after rating agency Moody's downgraded Greece's debt by three notches from Ba1 to B1. A Greek debt auction Tuesday was light on foreign bidders, noted Spiros Papadopoulos of National Australia Bank.
The market is turning its attention back to the eurozone debt crisis ahead of an upcoming EU leaders' meeting, with dealers anticipating an unimpressive outcome.
"The prospect of anything constructive, material coming out of this in terms of dealing with the sovereign problems is low," Ron Leven of Morgan Stanley told Dow Jones Newswires.
"There's not a cohesive sense of mission in terms of dealing with this problem and that's going to hurt the euro," Leven said.
On Friday, leaders of the 27-nation EU will meet in Brussels. A summit of the 17-nation eurozone will also be held to discuss the strengthening of national economic policies and the creation of a permanent rescue fund for member nations.
The dollar was mixed against other Asian currencies.
The unit rose to Sg$1.2697 from 1.2661 on Tuesday, to Tw$29.35 from 29.34, to 8,786.00 Indonesian rupiah from 8,782.50, and to 43.42 Philippine pesos from 43.33.
It fell to 1,115.85 Korean won from 1,116.65 and to 30.32 Thai baht from 30.40.
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