Asian shares made tentative gains on Friday as beaten-down Treasuries found buyers after US President Donald Trump's tax bill narrowly passed the lower house, although debt worries still lingered.

In Hong Kong, the benchmark Hang Seng Index had a flat opening, rising a mere 13.07 points, or 0.06 percent, to 23,557.38.

Across the border, the benchmark Shanghai Composite Index was down 0.1 percent to open at 3,376.87.

The Shenzhen Component Index opened 0.09 percent lower at 10,210.62.

The ChiNext Index, tracking China's Nasdaq-style board of growth enterprises, was down 0.12 percent to open at 2,043.2.

Australian shares edged higher, as gains in energy and bank stocks offset losses in miners and gold, with investors closing out a week shaped by the Reserve Bank of Australia's second interest rate cut in more than four years.

Overnight, purchasing managers' index data around the globe showed US business activity picked up pace in May, which helped Wall Street rise earlier yesterday before running into selling pressures and closing the day largely flat.

In contrast, disappointingly weak activity in Europe dragged shares there lower.

Nasdaq futures and S&P 500 futures both were flat.

The Republican-controlled US House voted by a slim margin to pass Trump's tax cut bill, which would fulfil many of his campaign pledges, but will increase the US$36.2 trillion US debt pile by US$3.8 trillion over the next decade.

Treasury yields, especially at the longer-dated end, have climbed on worries about US fiscal health in the run-up to the passage of the bill. That was exacerbated by the decision from Moody's last week to downgrade the US credit rating, citing rising debt.

In Asia, yields on super-long Japanese government bonds held near all-time highs on Friday.

The 30-year yields have jumped 23 basis points this week and were last at 3.175 per cent, which is being monitored closely by the Bank of Japan.

The MSCI's broadest index of Asia-Pacific shares outside Japan inched up 0.1 per cent on Friday but for the week it is still set for a loss of 0.4 per cent after five weeks of gains. (Reuters/Xinhua)