Asian share markets recouped early losses on Tuesday and the dollar edged away from a one-month trough against the yen, suggesting investors judged Democrat Hillary Clinton was winning her debate against Republican Donald Trump.

Markets have tended to see Clinton as the candidate of the status quo, while few are sure what a Trump presidency might mean for US foreign policy, trade and the domestic economy.

Japan's Nikkei more than halved its losses to be down 0.4 percent, while the dollar edged up to 100.74 yen from a low of around 100.08.

MSCI's broadest index of Asia-Pacific shares outside Japan bounced to be down just 0.01 percent, while South Korea and Shanghai nudged up 0.2 percent.

EMini futures for the S&P 500 recouped all its losses to trade 0.3 percent firmer.

"There's a thing called Trump thermometer," said David Bloom, London-based global head of forex strategy at HSBC.

"If you want to know who won the presidential debate, don't go to Twitter or Facebook. Just look at the dollar/Mexico peso."

The peso rose 0.7 percent and away from the all-time trough hit in recent days on concerns a Trump presidency would threaten Mexico's exports to the United States, its single biggest market.

Much the same goes for the Canadian dollar, which touched its lowest since March in early trade before gaining on the US counterpart.

Other safe-havens also ebbed, with yields on US 10-year Treasuries up a couple of basis points at 1.61 percent.

In commodity markets, oil ran into profit-taking having bounced 3 percent on Monday as the world's largest producers gathered in Algeria to discuss ways to tackle a crude glut that has battered prices for two years now.

Brent crude slipped 31 cents to $47.04 a barrel, while US crude dipped 25 cents to $45.68 per barrel.