Pakistani President Mamnoon Hussain has signed a bill, formally make it law, to merge country's tribal region with the northwestern Khyber Pakhtunkhwa province and giving equal rights to about 5 million people living in the rugged area bordering Afghanistan.

The move followed approvals of the bill in both the lower and upper houses of parliament. The legislation abolishes discriminatory laws under which Pakistan's tribal regions have been governed since British colonial rule.

Hussain signed the bill on Thursday, the same day that Pakistan Muslim League party's government ends its five-year term. Pakistanis will hold parliamentary elections on July 25 that will usher in a new Cabinet.

Outgoing Prime Minister Shahid Khaqan Abbasi is to resign later Thursday, after which caretaker premier, Nasir-ul-Mulk, takes over for the two-month interim period.