Rifts within the coalition have again appeared since it succeeded Monday in forcing former army strongman Pervez Musharraf to resign from the presidency.
Twin suicide blasts that killed at least 67 people outside Pakistan's main weapons-manufacturing complex Thursday were a bloody reminder of the threat to the South Asian country from Islamic extremists.
But by Friday, Pakistan's civilian leaders were again locked in talks on how to restore judges ousted by Musharraf last year and who should succeed him as head of state.
Pakistan's election commission announced Friday that lawmakers will elect the new president on Sept. 6.
The party of Nawaz Sharif, a two-time former prime minister and bitter foe of Musharraf, had threatened to quit the coalition without an agreement by Friday.
But after talks with other coalition leaders, Sharif set Wednesday as a new deadline for the restoration of the judges.
Sharif's party is the junior partner to the Pakistan People's Party (PPP) of assassinated former premier Benazir Bhutto. They joined forces against Musharraf after sweeping aside his allies in February parliamentary elections.
The United States and other Western countries, who had counted for years on Musharraf to counter al Qaeda and the Taliban, hoped the democratic mandate of the new government - made of up of moderate parties - would continue
Pakistan's military said Friday that it has killed up to 16 militants in a clash in the northwest. The dead included at least one suicide bomber. A military statement said the shootout broke out Friday near the town of Hangu when security forces stopped a suspicious vehicle at a checkpoint.
It said one person who got out of the vehicle and moved toward the checkpoint was shot by troops. Subsequently, explosives that he was carrying went off. The statement said a gunbattle with the remaining suspects ended when the vehicle itself blew up.
Last month, Pakistan's security services warned that a group of suicide bombers would fan out across the country in the coming weeks to target important locations, reported CBS News' Farhan Bokhari. At least 11 militants were arrested then, including five who were trained suicide bombers, during a raid in Lahore, Pakistan's second largest city,
"There are many indications to suggest that more attacks are planned. Pakistan could face a lot of bloodshed as it tries to deal with a very difficult problem," said a Western diplomat in Islamabad, who spoke to CBS News on condition of anonymity.
Ordinary Pakistanis are more anxious for the government to do something about the skyrocketing inflation and inequality holding much of the population in poverty.
But the main political parties, staffed by Pakistan's narrow elite, are traditional rivals whose election pledge to restore an independent judiciary is bogged down in political maneuvering.
Having granted smaller coalition partners a request for three extra days to consider the ramifications, he said the parties would draw up a resolution on restoring the judges and introduce it to Parliament on Monday.
"Technically, by Aug. 19, the judges should have been reinstated," he told reporters.
The resolution "should be debated on Monday and Tuesday, and on Wednesday this resolution should be passed and the judges should be reinstated," he said.
Sharif argues that a simple order from the prime minister is enough to restore the judges. But Zardari has consistently blocked that, arguing that it requires a constitutional amendment.
Musharraf, who was also army chief until November, imposed emergency rule and purged the Supreme Court to prevent it from disqualifying him from continuing as a civilian president.
Zardari, like Musharraf, accuses the judges of being too political. Analysts suggest his hostility could also be down to concern that they could reopen long-standing corruption cases against him dating back to his wife's two spells as prime minister in the 1990s.
Sharif, meanwhile, may view the judges as likely allies if he follows through with threats to have Musharraf tried for treason - a charge punishable by death.
Sharif has also been more reserved than Zardari about embracing Pakistan's unpopular role as a chief ally of the U.S.-led war on terrorism.
Many Pakistanis argue that Musharraf's use of the army against militant strongholds in the northwest has only increased sympathy for the militants and emboldened them to strike back with scores of suicide bombins over the past year.
Thursday's attack in Wah, a city 22 miles from the capital, Islamabad, was one of the country's deadliest-ever terrorist attacks.
A Taliban spokesman claimed responsibility, saying it was revenge for army operations in the Bajur region, a militant stronghold near the Afghan border.
As well as 67 confirmed dead, police said Friday that more than 100 people were wounded when the bombers struck outside two gates to the sprawling complex, just as workers were streaming through during a shift change.
The attack underscored the determination of insurgents to challenge the Pakistani state for control of swaths of territory in the troubled northwest regardless of who is in power.
Police said it could even have been worse.
Mohammed Saeed, a police official in Wah, said security forces had arrested a man they believe would have been a third bomber not far from the scene. An explosives-laden jacket was found at a nearby mosque, he said.