The call came amid worries in Washington that the new coalition government led by Prime Minister Yousuf Raza Gilani, which is negotiating with a Taliban commander, may strike a deal with militants and undermine a long 'war on terror' partnership.

Deputy Secretary of State John Negroponte said Islamabad recognised that bringing the mountainous and unpoliced Federally Administered Tribal Areas (Fata) under control was an urgent priority for Pakistan's own sake.

'But let me be clear: we will not be satisfied until all the violent extremism emanating from the Federally Administered Tribal Areas is brought under control,' he said at a forum of the Washington-based National Endowment for Democracy.

'It is unacceptable for extremists to use those areas to plan, train for, or execute attacks against Afghanistan, Pakistan, or the wider world,' he said.

'Their ongoing ability to do so is a barrier to lasting security, both regionally and internationally.' Mr Negroponte said Pakistan's government 'must bring the frontier area under its control as quickly as possible,' pointing out that Washington was prepared to provide 'appropriate assistance' in order to achieve that objective.

Mr Gilani's government, formed after the backers of key war on terror ally President Pervez Musharraf were defeated in elections in February, has pledged to completely overhaul Islamabad's counter terrorism pursuit.

It has been trying to reach a peace deal with a Taleban commander Baitullah Mehsud accused of masterminding the slaying of former premier Benazir Bhutto in December.

Warlord Mehsud declared a unilateral truce with security forces in the lawless tribal regions last month after officials said the government had drafted a peace agreement with Islamic militants.

But the militant halted talks last week because the government refused to withdraw its troops from his area.

Mr Negroponte warned that Americans 'don't want to see the tribal area being used as a platform for plotting and executing international terrorist activity against the West.

'So any kind of agreement or understanding which might be negotiated, we would have to look at in the light of those imperatives for United States policies,' he said.

The administration of US President George W. Bush has warned that Al-Qaeda was rebuilding itself in Pakistan's Fata and North West Frontier Province, both on the border with Afghanistan.

The Fata is also seen by Washington as a staging area for Al-Qaeda attacks in support of the Taleban in Afghanistan, where US and Nato troops have suffered heavy casualties battling a long drawn insurgency.

Mr Negroponte said the United States expected Pakistan's civilian and military leadership to be 'strong partners against violent extremists in Pakistan's frontier areas.'

To help extend the Pakistani government's authority into those regions, he said, the United States was implementing a multi-year programme to expand, equip, and train local security forces in the tribal areas.

A successful strategy in the tribal areas, he said, must include not only the possibility of military operations but also a serious and sustained economic development program and improvements in education and governance. -- AFP