Asian markets were mixed, with Tokyo surging thanks to a weakening yen after a weekend G20 meeting ended without accusing Japan of orchestrating a recent slide in its currency.
The Japanese unit resumed its downward trend as dealers welcomed the end of the Moscow talks, which came amid concerns that Japan's new aggressive monetary policy could spark a currency war.
Tokyo climbed 2.09 percent, or 234.04 points, to 11,407.87 and Sydney added 0.59 percent, or 29.5 points, to end at 5,063.4, around highs not seen for about four-and-a-half years thanks to strong corporate results.
Seoul was flat, edging up 0.73 points to 1,981.91.
However, Hong Kong eased 0.27 percent, or 62.62 points, to 23,381.94, while Shanghai, returning after a week-long Lunar New Year break, fell 0.45 percent, or 10.84 points, to 2,421.56.
The G20 finance ministers' statement issued Saturday said: "We will refrain from competitive devaluation," adding "we will not target our exchange rates for competitive purposes".
The pledge echoed a recent statement by the G7 richest nations. Neither named Tokyo as a currency manipulator.
The BoJ, under pressure from Japan's new conservative government, last month unveiled a plan for unlimited monetary easing and a target for two percent inflation as part of a bid to beat lingering deflation.
However, the moves sparked charges of manipulation, particularly in Europe, with some warning of a currency war in which nations weaken their units in a bid to boost exports.
In foreign exchange trade the dollar strengthened to 94.02 yen, from 93.53 yen in New York on Friday, while the euro bought 125.32 yen from 124.97 yen. The Japanese unit has lost about 17 percent against the dollar and 25 percent against the euro since November.
The euro also bought $1.3329 compared with $1.3360 in New York on Friday.
National Australia Bank said the yen's return to a weakening trend -- after rising before the G20 talks -- signalled "exchange rate shifts arising from appropriate domestic monetary and fiscal policies will not be criticised or challenged".
"But direct reference to currencies as a policy objective will be," it added in a note.
"We believe this means the yen is free to weaken, but Japanese officials must refrain from being seen to be goading the yen to weaker levels."
And Shane Oliver, head of investment strategy and chief economist at AMP Capital in Sydney, told Dow Jones Newswires the G20 "doesn't seem to have done anything to prevent Japan from stimulating its economy".
In Shanghai, shares rose on their first day after the long holiday, with dealers optimistic about the domestic economy following strong trade data at the beginning of the month.
Oil prices were mixed, with New York's main contract, light sweet crude for delivery in March, down 32 cents to $95.54 a barrel in the afternoon while Brent North Sea crude for delivery in April added 18 cents to $117.84.
Gold was at $1,614.10 at 0820 GMT, compared with $1,628.08 late Friday.
In other markets:
Taipei rose 0.47 percent, or 36.88 points, to 7,943.53.
Taiwan Semiconductor Manufacturing Co. was 1.90 percent higher at Tw$107.0 while Cathay Financial Holdings surged 5.10 percent to Tw$37.1.
Manila closed 0.67 percent higher, adding 43.59 points to 6,565.23.
Property firm Megaworld rose 2.7 percent to 3.78 pesos and Philippine Long Distance Telephone Co. added 0.4 percent at 2,850 pesos.
Wellington rose 0.42 percent, or 17.74 points, to 4,214.48.
Telecom was up 1.58 percent at NZ$2.26, Fletcher Building added 1.47 percent to NZ$9.00 and Air New Zealand eased 0.39 percent to NZ$1.26.