The death penalty is part of PNG's criminal code but the sentence has never been carried out.
"The reason it didn't move forward to implementation is we did not have the methodology," Attorney-General Kerenga Kua told AAP.
"The mechanism has not been prescribed ... coupled with the political will not being there.
"But it is there now."
He says there are 10 convicted criminals on death row.
The last death sentence carried out in PNG was during Australian colonial rule in 1954.
Mr Kua says crimes such as piracy, aggravated murder and treason should attract the sentence.
"A very narrow band of crimes allow for the death penalty, but it only applies in the most aggravated circumstance of wilful murder," he said.
"Then you have piracy, which is growing in the country.
"We need to stamp it out."
National Capital District governor and human rights lawyer Powes Parkop opposes the plan.
"It is an inhuman form of punishment and therefore should be unconstitutional," he told The National newspaper last week.
"There is no empirical evidence to show that such punishment has been a deterrence to crime generally or the type of crime for which it is prescribed as a penalty."
He said in the United States, where some states have the death penalty, there is no evidence to show it has reduced crime.
The Catholic church of PNG has also voiced its opposition to the death penalty, with General Secretary Father Victor Roach warning it could prolong the practice of payback among tribes.