After the Labour Party took control of the two cities in last month's local elections, it is expected to start trialing the policy in both cities, Aftenposten newspaper said on Friday.
“We have agreed not to prevent a trial of heroin-assisted treatment for the heaviest abusers, if the Bergen health authority wants to begin such an effort again,” Harald Schjelderup (Ap), the newly appointed Chief Commissioner for Bergen told VG.
At the same time, Labour's Christian Democrat and Liberal allies in the city's council are willing to back the opening of special safe rooms where heroin addicts and smoke and inject heroin and other drugs.
In Oslo, 64-year-old Marianne Borgen, who was appointed mayor on Friday night, is expected to bring in a new drugs treatment policy.
The policy agreement Labour has agreed with the Green Party and the Socialist Left party opened the way for a trial of heroin treatment in a strictly controlled trial.
But this must be backed by Norway's national parliament, which in 2012 rejected a motion to allow treatment with heroin.
According to a 2014 EU drugs report, Norway at 76 per million per year, has the second highest rate of death from drug overdose in the world after Estonia.
In Estonia the rate have soared to 190 per million from below 80 since 2008 because of an explosion in the use of the potent synthetic opioid Fentanyl.