Investors remained cautious over the possible economic impact of Hurricane Irma as it chewed its way up the Florida coast, knocking out electricity to 2.5 million homes and businesses statewide.

Nikkei futures were trading up 0.8 percent after Pyongyang held a massive celebration to congratulate the nuclear scientists and technicians who steered the country's sixth and largest nuclear test a week ago.

The United States and its allies had been bracing for another long-range missile launch in time for the 69th anniversary of North Korea's founding on Saturday.

The sense of relief was enough to lift E-Mini futures for the S&P 500 by 0.3 percent, while Treasury 10-year note futures fell 10 ticks.

The U.S. dollar edged up to 108.43 yen and away from Friday's 10-month trough of 107.32. Against a basket of currencies, the dollar added 0.2 percent to 91.521 but that was still uncomfortably close to last week's 2-1/2 year low of 91.011.

The euro eased to $1.2015, having hit a top of $1.2092 on Friday amid speculation the European Central Bank was closer to starting a wind-back of its stimulus program.

ECB officials last week generally agreed their next move would be to cut their bond purchases and discussed a range of options, Reuters reported.

China's central bank was also a focus in Asia after sources said it plans to scrap reserve requirements for financial institutions settling foreign exchange forward yuan positions with effect from Monday.

"The removal potentially makes it easier for traders to purchase the USD, easing the pressure for yuan appreciation," said analysts at ANZ in a note.

"The change likely signals some discomfort about the stronger yuan and its impact on Chinese exports."

The dollar was last up 0.25 percent against the offshore yuan at 6.5013 yuan, off a low of 6.4437.

There were also reports Beijing was planning to shut down local crypto-currency exchanges, dealing a blow to Bitcoin's recent stellar rally.

Bitcoin was quoted down 0.8 percent at $4,274 on the BitStamp platform, off the recent record high of nearly $5,000.

In commodity markets, gold softened 0.7 percent to $1,337.01 an ounce and away from a one-year peak of $1,357.54.

Oil prices regained a little ground after falling sharply on Friday amid worries that energy demand would be hit hard by Hurricane Irma.

U.S. crude was trading 22 cents firmer at $47.70 a barrel, while Brent rose 17 cents to $53.95.

(Editing by Richard Pullin)