Global shares have ticked up with US President Donald Trump reportedly signing into law a $US2.3 ($A3.0) trillion pandemic aid and spending package.

US S&P futures last traded up 0.4 per cent.

The futures had earlier reversed losses after a cryptic tweet by Trump – “Good news on Covid Relief Bill. Information to follow” – helped offset worries about further delay in stimulus spendings.

A source later said he had approved the bill.

Japan’s Nikkei inched up 0.4 per cent. MSCI’s broadest index of Asia-Pacific shares outside Japan rose 0.2 per cent, though trade is slow with many markets still closed for holiday.

“It is positive for markets that we no longer have a chaos over stimulus, considering there was a chance of a partial government shutdown,” said Masahiro Ichikawa at Sumimoto Mitsui DS Asset Management.

“But on the other hand, markets have talked about that stimulus for a long time and I would say most of it has been already priced in.”

Trump had refused to sign into law the pandemic aid and spending package Congress has passed, demanding stimulus cheques for struggling Americans be increased.

Trump’s threat to not sign the package had already shuttered an emergency unemployment aid program and threatened a partial federal government shutdown at midnight on Monday.

US bond yields edged up in its first trade after Christmas, with the 10-year US Treasuries yield up 0.6 basis point at 0.930 per cent.

The rollouts of COVID-19 vaccines are also bolstering hopes of more economic normalisation next year, with Europe launching a mass vaccination drive on Sunday.

That offset alarms over a new highly infectious variant of the virus raging in the southeast of England and confirmed in many other countries, including Japan, France and Canada, over the weekend.

Major currencies were little changed.

The euro traded at $1.2204, a tad below its 2-1/2-year high of $1.22735, while the yen changed hands at 103.56 per dollar.

The British pound changed hands at $1.3565, not far from a 2-1/2-year high of $1.3625 hit earlier this month after Britain and the European Union reached an agreement on trade framework after Brexit.

Bitcoin extended gains over the weekend to reach a new high of $28,377.94 before stepping back to $26,457.32, bringing the total value of the cryptocurrency in circulation to over $US500 billion.

Oil prices edged down a tad, with US crude futures down 0.8 per cent at $US47.85 per barrel.