A day after Ms Gallagher outlined her proposal for an cross-jurisdiction trial and ACT representative to join a working group advising the NSW government, a spokesman for Premier Mike Baird indicated a willingness only to consider future collaboration with other jurisdictions.

It is understood the Liberal-National Coalition-led state will go it alone on the working group process, due to report back by the end of the year.

"The NSW government's reforms are about compassionate care and seek to explore the role that cannabis can play in providing relief for patients suffering from a range of debilitating or terminal illnesses," the spokesman said.

"The premier welcomes the ACT government's interest in the medical cannabis clinical trial to be established by the NSW government.

"The NSW government working group will explore opportunities to collaborate with other jurisdictions, including the ACT, as work progresses."

Mr Baird is expected to reply to Ms Gallagher's September 17 letter in coming days.

The chief minister answered questions and criticism about medical cannabis during a social media forum on Tuesday night.

Serving in her dual role as health minister, Ms Gallagher's calls for a Commonwealth-led strategy on introduction of medical cannabis won support on Tuesday.

In an August letter to federal Health Minister Peter Dutton, she proposed the National Health and Medical Research Council conduct an Australia-wide clinical trial and the Therapeutic Goods Administration consider how medical cannabis could be licensed for use.

University of Canberra professor of pharmacy Gabrielle Cooper said health professionals around the world recognised evidence supporting the therapeutic role of cannabis in the management of symptoms associated with chronic conditions and end-of-life diseases.

Dr Cooper welcomed Ms Gallagher's suggestion of a national trial.

"Currently in Australia we have limited-prescription pharmaceutical cannabis products available, approved and regulated by the Therapeutic Goods Administration," she said.

"These pharmaceuticals have been assessed for quality, safety and clinical efficacy, as are all the other prescription therapeutic agents available and frequently subsidised in Australia.

"As with all medications, potential adverse effects may occur. But the therapeutic risk-benefit ratio is judiciously balanced with clinical need."

A spokesman for Mr Dutton did not directly respond to questions about Ms Gallagher's proposal, including one for a national summit of chief health officers.

"The commonwealth position is influenced by the advice of the commonwealth chief medical officer," he said. "The government is continuing to speak with the states and territories on what is a vexed issue."

Prime Minister Tony Abbott is among the growing list of political leaders who have offered support for medical cannabis use. States including Victoria are also moving towards clinical trials.

Opposition Leader Jeremy Hanson, who serves as Liberal health spokesman, said the ACT shouldn't be part of the NSW plan.

He called for a consistent national approach to consideration of cannabis. But he said the NSW trial was a matter for that state, and its findings could help guide future territory policy.

The issue is expected to be discussed by state and territory health ministers at a meeting in Melbourne on Friday.

Ms Gallagher said national security concerns and reforms to the federation were likely to dominate a Council of Australian Governments meeting to be held in Canberra on the same day.

An ACT Legislative Assembly committee is considering a bill from Greens minister Shane Rattenbury which would allow terminally and chronically ill Canberrans to grow cannabis and use the drug as part of their treatment.

The committee's report is expected by June 2015.