Adrian Richardson, 30, drove his small Peugot hatchback at the gates of the building - one of the ACT's most secure - about 5.45pm on Wednesday July 10.

His actions caused a significant security response from guards, police and local emergency services, with his car causing up to $100,000 damage to the gate and managing to breach the embassy's perimeter.

US ambassador Jeffrey Bleich and several other dignitaries were inside the building, and Richardson was arrested and charged with damaging the premises of an internationally protected person.

But in his first appearance in the ACT Magistrates Court, evidence strongly suggested that Richardson was mentally ill at the time of the offence.

He had checked himself out of the secure mental health ward at the Canberra Hospital earlier that day, after an order to keep him there lapsed.

Richardson came back before the courts on Tuesday morning, and mental health assessments showed he suffers from a delusional disorder.

But his case has now encountered difficulties posed by the ACT's mental health system. The ACT lacks a medium- to long-term secure mental health facility, the completion of which may be delayed until 2017.

The Adult Mental Health Unit at the Canberra Hospital has told the court it can hold Richardson only for two to three days, and recommended sending him to his home state of Queensland for treatment.

But the law requires him to be dealt with in the ACT, and his legal aid lawyer Brian Liddy raised fears that there was nowhere else for him to go other than the hospital or prison.

Mr Liddy remarked that this was ''an indictment on our jurisdiction, it seems to me''.

The court has put in place a short-term fix to address the concerns of Commonwealth prosecutors, who fear Richardson may reoffend or fail to appear in court.

Chief Magistrate Lorraine Walker bailed him to reside at the Adult Mental Health Unit, and asked Mental Health ACT to notify police if he is discharged for any

reason, so he can immediately be brought back before the courts.

The nuances of the case - given the building was occupied by internationally protected persons - mean prosecutors need to obtain the consent of the federal Attorney-General Mark Dreyfus before they can pursue charges against Richardson.

Richardson will be back before court on Friday.

He is prohibited from entering the suburb of Yarralumla, contacting staff at the US embassy or leaving the ACT.

Fairfax Media revealed on Monday that the government could use special legislation to bypass planning laws and build the territory's desperately needed secure mental health unit facility.

The extreme measure is one option Chief Minister Katy Gallagher is considering to speed up construction of the 25-bed medium secure facility.

A spokesman for Ms Gallagher said on Tuesday: ''The minister is actively working on options to bring the delivery of a forensic mental health unit forward from its current expected completion date in mid-2017. The government is considering a range of options to deliver this crucial piece of mental health infrastructure quickly.''

The government would not respond further to Mr Liddy's comments as ''it would be inappropriate to comment further on specific cases before a court''.

But the spokesman said Richardson was able to be treated in the adult mental health unit for as long as clinically needed.

''Discussions are in place to repatriate him to his home state, when required,'' the spokesman said.

Opposition Leader Jeremy Hanson has demanded that the government take responsibility for ''a decade of failure'' in the planning of a forensic facility. He said too many patients had been caught between the health and justice systems.

''Whatever the measure is, it's going to be a retrofit stopgap for a decade of failure in politics,'' Mr Hanson said.

''Katy Gallagher is the one who has to take responsibility for this.''