The ACT government will bid for funding from a new Major Projects Business Case Fund to go towards a better Canberra-Sydney rail link.

Responding to Tuesday's federal budget, ACT Chief Minister Andrew Barr said Canberra would also seek to become the home of the new national space agency.

Mr Barr welcomed the Barton Highway duplication and while his government would examine the Monaro Highway business case, he considered the funding could be better spent on the Pialligo Avenue duplication.

"We're pleased to see funding for repairs to the National Gallery, but very concerned to see staff sacked from the National Archives and National Library," Mr Barr told AAP.