Pakistan will launch an operation against militants in restive South Waziristan "imminently", Interior Minister Rehman Malik has said.
He was speaking after troops stormed a building at an army base in Rawalpindi, rescuing dozens of people taken hostage in an attack by militants.
Mr Malik blamed the attack, in which 19 died, on the Taliban and al-Qaeda whose strongholds are in South Waziristan.
One militant, thought to be the group's leader, was arrested.
Mr Malik said the government had given its approval to an operation in South Waziristan, and it was now up to the army to decide on its timing.
"The operation is imminent," he said, according to Reuters news agency.
The army has been preparing for a major operation in South Waziristan since it successfully cleared the Swat valley of militants in September.
Correspondents say a string of recent militant attacks have been attempts to dissuade the army from mounting an assault on South Waziristan.
The military in Pakistan had been trying to build public confidence ahead of a major new offensive, says the BBC's Aleem Maqbool in Islamabad.
But Pakistanis will be wondering how safe the army can keep them when militants can strike back with such audacity, our correspondent adds.
The attack on Rawalpindi, an army town to the south of the capital, Islamabad, prompted US Secretary of State Hillary Clinton, speaking during a visit to London, to say militants in Pakistan were increasingly threatening the authority of the state.
But she said the US saw no evidence they were going to succeed, or that Pakistan's nuclear arsenal was at threat.
Mr Malik also congratulated the army on its success in ending the hostage situation.
RECENT MILITANT ATTACKS
24 Sept - Seven pro-government tribal elders killed by militants in town of Janikhel, north-western Pakistan
26 Sept - At least 16 people killed in two suicide car bombs, in Peshawar and Bannu
5 Oct - Suicide bomber attacks UN offices in Islamabad killing five
9 Oct - At least 50 killed in suspected suicide bombing in Peshawar
Our correspondent says the attack will be a huge embarrassment to the authorities, as it happened in one of the most secure areas in the country.
It began on Saturday when militants drove up to the army compound, shooting and throwing grenades. Six soldiers and four militants died in the initial assault.
The authorities declared the situation over, but it later transpired that some militants had infiltrated the compound and were holding hostages.
Pakistani special forces stormed the compound just before dawn on Sunday.
In the ensuing fighting, three hostages, two soldiers and four militants were killed. Another militant was badly wounded and later arrested.
The military said later that the surviving militant, named as Aqeel or Dr Usman, was the leader of the group and was also suspected of masterminding an attack on the Sri Lankan cricket team in Lahore in March.
Brigadier Anwar Ul Haq was killed in the attack
Senior military officials and civilian personnel were reported to be among the hostages.
The attack followed a series of bombings in north-western Pakistan. On Friday at least 50 died in a blast in Peshawar.
In recent days Taliban positions in the tribal areas have been bombed by the air force, amid speculation that the army's offensive there is soon to be intensified, says our correspondent.
There was a period of relative quiet in August after Taliban leader Baitullah Mehsud was killed, but the rate of militant attacks has increased since then, he adds.
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