By Barbara Plett
BBC News, Islamabad
The air strikes are hugely controversial
US air strikes in Pakistan's troubled tribal belt are "seriously undermining" public support for the government, a senior official has told the BBC.
North West Frontier Province governor Owais Ghani said such actions could make it impossible for the government to keep struggling against militancy.
The US is frustrated with what they see as insufficient efforts by Islamabad to fight militants on the Afghan border.
That has fuelled Pakistani concerns of increased US intervention.
Mr Ghani said that he would be "deeply concerned" about any increase in unilateral US airstrikes in tribal areas.
"This has a great backlash in the public sentiment, public opinion," he said. "It seriously undermines the much needed backing of the population.
Today Afghanistan is a narco-state, that itself is a huge contributor of instability in Afghanistan
NWFP Governor Owais Ghani
"Therefore it is very, very undesirable, and if it continues I think the pressure is already building up. If that goes beyond a certain point and people react, no government, political or military, will be able to continue. So I think that it's very important they understand the implications."
American military officials are alarmed by Pakistan's strategy of pursuing peace deals with pro-Taleban tribesmen near the Afghan border.
Last week top US military officer Admiral Mike Mullen said this increased the flow of militants into Afghanistan to combat Nato troops.
He also said the peace process allowed more foreign fighters to operate in the region, reflecting American concerns that al-Qaeda is regrouping in the tribal areas and plotting its next 9/11-style attack against the United States.
Such public criticism has fuelled speculation that the Americans will take matters into their own hands.
According to numerous reports, earlier this year the Americans did have permission from Pakistan for limited air strikes against al-Qaeda targets. But the new government elected in February asked them to stop, because these hits roused anger and led to revenge attacks.
The Pakistani authorities say they are determined to stop a campaign of suicide bombings triggered largely by military strikes - both Pakistani and American - in the tribal areas.
They also say that seven years of military action has only radicalised the tribes along the Afghan border, strengthened the Taleban and weakened state institutions.
So they have turned to political negotiations and economic development to try to wrest back their authority, along with the selective use of force.
Officially Washington has not said anything about an increase in direct US action in the tribal belt, but American media reports suggest it is being seriously considered.
Senior security officials here have also said the last three missile strikes inside Pakistani territory were not co-ordinated with Pakistan, and they believe an increase is probable.
Some think that is at least partly because the US President George W Bush wants to arrest or eliminate a top al-Qaeda leader before the end of his term.
Mr Ghani repeated Pakistani complaints that it was in fact Nato and Afghan forces that were not pulling their weight in monitoring the long and mountainous frontier.
It's argued that the US is undermining support for the authorities
He said that Pakistani check posts outnumbered those on the Afghan side by 10 to one, and complained that Afghanistan refused Pakistani offers to fence the border.
He also countered American and Afghan assertions that Taleban sanctuaries in the tribal areas were the main factor fuelling the Afghan insurgency.
He pointed to the thriving opium trade and the weakness of social and political structures inside Afghanistan.
"Today Afghanistan is a narco-state, that itself is a huge contributor of instability in Afghanistan."
Mr Ghani said Afghanistan was "a failed state now, which means it's a long term problem."
"Placing all the blame at Pakistan's doorstep is wrong."
Stability between the two countries was linked, he argued, and there would be no peace in the tribal areas without peace in Afghanistan, which required talking to the Taleban.
"The bottom line is simple," he said, "that all Afghan power groups, irrespective of the length of their beards, are given due political space, they need that political share."