Overnight comments from the European Central Bank chief heightened expectations of easing steps in the euro zone as Asian stocks erased early modest gains and the euro steadied.
"Short covering has been continuing since last week's strong China PMI data and U.S. housing data," said Norihiro Fujito, senior investment strategist at Mitsubishi UFJ Morgan Stanley Securities. "The main buyers are short-term investors like derivatives players and hedge funds."
US and UK markets were closed for holidays on Monday, giving Asian shares fewer directional cues than usual.
The holidays also crimped foreign exchange volumes to less than half of their daily averages. While thin conditions sometimes amplify market moves, major currency pairs quietly stuck to recent ranges.
ECB chief Mario Draghi on Monday continued to hint at coming measures, saying the ECB must be "particularly watchful" for any negative price spiral in the euro zone, and that "more pre-emptive action may be warranted."
Later today, Draghi is scheduled to participate in an armchair discussion in the final day of the ECB forum underway in Portugal.
Reuters reported earlier this month that the ECB is preparing a package of policy options for its June 5 meeting. It includes cuts in all its interest rates as well as targeted measures aimed at boosting lending to smaller firms.
By contrast, current and former Japanese central bankers familiar with internal discussions say an informal debate is under way at the Bank of Japan on how to prepare for an eventual exit from its massive quantitative easing program.
The yen was steady against the dollar, which bought 101.96 JPY= and remained not far from its 1-1/2 week high of 102.05 marked on Monday.
Investors kept a wary eye on Ukraine, which launched air strikes and a paratrooper assault against pro-Russian rebels who seized an airport on Monday.
The escalation in the ongoing crisis was tempered by the decisive win for billionaire Petro Poroshenko in Ukraine's weekend presidential election, which many hope will help bring some stability to the situation.
London copper edged to its highest in nearly three months on Tuesday as markets reopened after a holiday weekend, underpinned by buying from top consumer China and expectations of monetary easing in Europe. It was last fetching $6,935 a tonne.