Enda Kenny said he would back such a proposal if it emerged from the all-party talks.
The current talks are being chaired by the British and Irish governments.
Mr Kenny was responding to a suggestion from Micheal Martin, the leader of the main opposition party, Fianna Fail.
The Sinn Fein leader, Gerry Adams, said his party was "totally and absolutely opposed to criminality of all kinds".
Mr Adams added that he and other senior Sinn Fein members had paid a price for such opposition by having their homes targeted and their lives threatened.
He said Sinn Fein was was accountable to one grouping only -  the electorate, and not to any other organisation.
Yesterday's report into paramilitarism quoted IRA members as believing that the Provisional IRA Army Council oversees Sinn Fein's political strategy.
The Taoiseach (Irish prime minister) has told the DÃ¡il that he would be open to the idea of a cross-border joint agency that tackled crime in all its forms.