U.N. High Commissioner for Human Rights Navi Pillay spoke to reporters as she wrapped up a tour of Pakistan this week.
Pillay said she secured assurances from Pakistani authorities that it was committed to codifying laws on torture.
"This is very welcome news, since it is essential that a clear definition of torture and the fact that it is a crime under any circumstances must be enshrined in national law if the practice is to be eradicated," she said.
Human Rights Watch this week said Pakistani forces are suspected of having a role in enforced disappearances and abuses targeting members of minority ethnic communities.
On the rights of women the picture remains "grim," Pillay said. A group of women this week were condemned to death by a tribal council in Kohistan in northern Pakistan for singing and dancing with men during a wedding in apparent violation of tribal law.
Pillay said the case is illustrative of the problems associated with parallel legal systems in Pakistan.
She added, however, that the Pakistani Supreme Court observed that tribal councils are illegal.