Some 500 women are killed each year in Pakistan at the hands of family members.
Pakistan's parliament unanimously passed a legislation against "honour killings" on Thursday, three months after the murder of outspoken social media star Qandeel Baloch.
A joint session of the lower and upper houses of parliament, broadcast live on television, approved the new anti-honour killing law, removing a loophole in existing law that allows killers to walk free after being pardoned by family members.
"Laws are supposed to guide better behaviour, not allow destructive behaviour to continue with impunity," said former senator Sughra Imam, who initially put forward the bill.
Some 500 women are killed each year in Pakistan at the hands of family members over perceived damage to "honour" that can involve eloping, fraternising with men or any other infraction against conservative values relating to women.
In most cases, the victim is a woman and the killer is a relative who escapes punishment by seeking forgiveness for the crime from family members.
Under the new law, relatives can forgive convicts in the case of a death sentence, but they would still have to face a mandatory life sentence.
An anti-rape law, which makes it mandatory that a perpetrator gets 25 years in jail, was also passed in the same parliamentary session.
"These bills are hugely important for Pakistani women, where rape conviction rates were almost non-existent, due in large part to various technical obstacles to accessing justice," said Yasmeen Hassan, Global Executive Director at Equality Now.
"We hope that these new laws will help generate a cultural shift in Pakistani society and that women will be able to live their lives in safety," Hassan told Reuters.
Sharmeen Obaid-Chinoy, whose documentary on honour killings won an Oscar this year, posted on Twitter: "Thank you to PM Nawaz Sharif for keeping his promise".
The government of Prime Minister Sharif has faced mounting pressure to pass the law after the brother of Baloch was arrested in connection with her strangling death.
© Thomson Reuters 2016