Mr Barr has also asked Mr Turnbull to boost defence investment in Canberra, and has signalled he will soon take the ACT government's plans for an extended light rail route to the Commonwealth for potential funding.

In the letter, sent on Monday, Mr Barr offers the Prime Minister his congratulations for winning the election and forming government, before setting out the ACT government's priorities, including his concern over a plan to move hundreds of public servants away from Canberra.

Agriculture Minister Barnaby Joyce announced during the election campaign that the Coalition would move the Australian Pesticides and Veterinary Medicines Authority from Canberra to Armidale, which sits in Mr Joyce's electorate of New England.

The move sparked significant opposition from a range of groups, including Mr Joyce's Coalition colleague, ACT Senator Zed Seselja.

Animal Medicines Australia, CropLife Australia, the National Farmers Federation, and public service unions are also against the plan.

Mr Barr told Mr Turnbull this week that the move would undermine a key strength of the federal public service - the centralisation of public policy expertise.

"While I support the move of a small to medium federal agency into Gungahlin to create greater demand for small businesses and facilities, I am concerned about the relocation of the Australian Pesticides and Veterinary Medicines Authority to Armidale," he wrote.

"Aside from the impost on workers having to relocate, the strength of the federal public service in Canberra lies in the co-location of high level public policy expertise.

"The relocation of National Disability Insurance Agency staff to Geelong and Australian Taxation Office to Gosford and other recent examples."

Mr Barr also sought to further cement defence investment in the ACT.

According to Invest Canberra, the Department of Defence already spends $1 billion a year directly in the ACT.

There are 13,000 military and civilian Department of Defence personnel in the region, and 10,000 private sector defence and security workers.

Mr Barr told Mr Turnbull that further development of the defence industry in Canberra was a "natural fit with the skills and expertise in the Canberra economy".

"I have written to [Defence Industry Minister Christopher] Pyne detailing the defence industry capability across the ACT and surrounding region, and the opportunities that can be derived in association with our academic and innovation sector," he said.

Mr Barr also raised the planned extensions of the light rail network in the ACT.

Possible options for extension, which could go from the city to Belconnen, Woden, the airport, or the Parliamentary Triangle, were released last week by the ACT Government.

Mr Barr said he "hoped to be in a position to present this to you and your Minister for Urban Infrastructure shortly".

There were also renewed calls for reforms to the dual planning system of the ACT and National Capital Authority, and a proposal for a cities deal incorporating Canberra and the region.

Such a deal would be hoped to provide better transport infrastructure between Canberra, Queanbeyan, Yass, and other regional centres that have a high volume of commuter traffic.

Mr Barr also praised the federal government's $50 million commitment to upgrade the Barton Highway, and asked Mr Turnbull for more details on timing.