Samaraweera told parliament yesterday that the process would be completely domestic and dismissed the Opposition claim that it would instead be a hybrid mechanism and would also investigate war-crimes allegations.
"I wish to stress that this would be a Sri Lankan process, not a hybrid process. It will be the Sri Lankan institutions and systems who will be implementing the process," he said.
The resolution co-sponsored by Sri Lanka and drafted by the US has called for a domestic inquiry involving foreign experts.
The Opposition argued that the resolution was a "give in" to the US, and despite government assurances there will be a "hybrid court" (involving foreigners) to try Sri Lankan military officials.
Sri Lanka's new government under President Maithripala Sirisena, however, says that better international engagements - since the defeat of former president Mahinda Rajapaksa - it was able to prevent Sri Lankan political and military leaders from being tried in international court.
The UN has estimated that 40,000 people died, many of them civilians, during the 26-year civil war.
Sri Lanka opted for a domestic mechanism despite the UN rights chief Seid Raad Al Hussein called for a hybrid court to carry out prosecutions into the rights abuse cases.
Samaraweera said to prevent violence, abuse and impunity and to ensure the recognition of the suffering of those who had lost loved ones, the government proposed to set up a truth commission and a compassionate council consisting of religious leaders.
