Pakistani Prime Minister Nawaz Sharif pledged to continue a military operation against Taliban insurgents in their stronghold of North Waziristan until peace returns to the country.
"I am confident this operation will be a harbinger of peace and stability," Sharif said in a speech in Parliament on Monday, his first comments since the military took action. "The decision on a decisive operation was taken with full consensus."
The army said on Sunday it would target local and foreign militants in North Waziristan, a tribal region near the Afghan border the US has called the "epicentre" of terrorism. The operation, long sought by the US, comes a week after militants attacked the country's biggest international airport.
Public opinion in Pakistan is shifting in favour of stronger action against fighters who were previously seen locally as more of a threat to US interests. The Taliban wants to impose its version of Islamic law in Pakistan, which includes a ban on music and stricter rules for women.
"At stake is the future of Pakistan," said Mahmud Ali Durrani, a former national security chief.
"Do we want a Talibanised Pakistan or do we want to live according to the constitution, democracy? If we want to live according to our constitution and democracy then we have to fight for it, because they are the kind of people who don't believe in these things."
The Tehreek-e-Taliban Pakistan, or Pakistani Taliban, has warned foreign investors to leave the country.
"We're in a state of war," Shahidullah Shahid, a spokesman for the group, said in a statement. "Foreign investors, airlines, and multinational companies should cut off business with Pakistan immediately and leave the country or else they will be responsible for their damage themselves."
Pakistan's foreign direct investment fell 13 per cent to US$751 million in the ten months ended April, from US$862 million year ago, according to central bank data.
Sharif's party won an election last year after pledging peace talks with the Pakistani Taliban, the group at the forefront of an insurgency that has killed 50,000 people since 2001. Negotiations that began in March collapsed over the Taliban's demand for prisoner releases even before progress on issues such as sharia law.
After Taliban and Uzbek militants attacked Karachi's international airport, killing 18 security officials and other staff, the US resumed drone attacks in North Waziristan following a six-month pause.
On Monday Pakistani jets destroyed six hideouts and killed 27 militants in the area, taking the death toll to 167 in two days of air strikes, the military said. Ten insurgents were shot dead in a separate battle, it said. Six soldiers were killed and three were injured when an explosion hit the area, the military added.
Troops had cordoned off all militant strongholds, including the two main towns of Mir Ali and Miranshah, and had been deployed along the border with Afghanistan to prevent combatants fleeing the country, the military said. Pakistan had also sought help from Afghan security forces to seal the border.
More than 61,000 people have fled North Waziristan through the town of Bannu since a military air strike that killed more than 60 militants on May 21, according to the local government in Bannu.
Another 6,500 people from the area, including 1,500 children, fled to Afghanistan, said Mobarez Mohammad Zadran, a spokesman for the Afghan border province of Khost.