Benazir Bhutto's death has rocked the Afghan government, which had seen in her the chance of a closer alliance with Pakistan against extremism despite her links to the Taliban's creation, officials said.
Afghan President Hamid Karzai met Bhutto for talks during a state visit to Pakistan just hours before she was killed Thursday in a shooting and suicide bombing.
The president later described Bhutto's death as a big loss and blamed those who were afraid of her strength and vision, while Pakistan's government pointed the finger at al Qaeda. "We were shocked," said Karzai's chief spokesman Homayun Hamidzada.
Bhutto had understood the difficulties neighbouring Afghanistan and Pakistan faced amid a wave of unrest in both countries, including a spike in suicide attacks, Hamidzada said.
"She said if she was re-elected she would work closely with the international community and the government of Afghanistan to address their common threats of terrorism and extremism," he said. Bhutto's Pakistan People's Party was the frontrunner for elections due in the country in January 8.
"She had good relations with us," said foreign ministry spokesman Sultan Ahmad Baheen, whereas observers have described Karzai's relationship with Pakistani President Pervez Musharraf as improving but testy.
"It is very disappointing for us to see her absence from the Pakistan political scene," said Davood Moradian, a foreign ministry adviser. Kabul had been looking forward to Benazir giving voice to the moderate Muslims of Pakistan, he said.
"But we are hoping that the way she was murdered by terrorists will provide momentum for the international community to see a long-term solution to the problems."
The Afghan government had seen in Benazir the "one major democratic force" in Pakistan, a senior government official said on condition of anonymity. "It was not just the government of Afghanistan that was putting a lot of hope on her, it was the whole world," he said.
She was committed to fighting extremists and to controlling the fundamentalist religious schools that spawn militants, he said, adding she also wanted to raise awareness of the consequences of extremism. "Of course she had a troubled past, but looking ahead - she was one of the few credible Pakistan alternatives."
The Taliban took up arms in chaotic southern Afghanistan and swept to power with funding and support from Pakistan's military during Benazir's second term as premier, between 1993 and 1996.
Author Steve Coll says in his book on Afghanistan-Ghost Wars-that Benazir had admitted in a 2002 interview to supporting the movement, which Pakistan initially used to protect a trade route. "I became slowly, slowly sucked into it," Bhutto is quoted as saying. "It started out with a little fuel, then it became machinery."
The support grew and Pakistan went on to become one of only three countries that supported the Islamic regime as it gave sanctuary to al Qaeda. A US-led invasion drove out the Taliban government because it refused to hand over al Qaeda leaders for the 9/11 attacks, and militant leaders are believed to have fled to Pakistan.
Hamidullah Tarzi, a former government minister, said the killing of Bhutto may be a filip for those responsible and for militants in frontier areas that have been semi-autonomous for centuries. But an "aggressive policy" towards these areas could only backfire, he said, adding Bhutto's suggestion that she would allow a US military strike on Pakistan to eliminate Osama bin Laden may have been her "undoing."