American defense secretary Leon Panetta said on Thursday, “we are reaching the limits of our patience” with Pakistan as the country fails to root out the sanctuaries for Afghan insurgents that exist on its side of the border.

On a visit to Kabul, the capital of Afghanistan, Panetta urged Pakistan to “take steps” to dismantle the insurgent camps. “It is difficult to achieve peace in Afghanistan as long as there is safe haven for terrorists in Pakistan,” he told reporters.

The United States have long pushed Pakistan to expand its war effort against Islamic radicals within its borders but Islamabad insists that it has to first consolidate gains in South Waziristan and Swat before opening another front against the insurgents in the western frontier area.

Relations between the two allies in the War on Terror have been soured by American drone attacks on suspected terrorist sites in Pakistan — which were expanded into North Waziristan and the tribal regions west of Peshawar last year — as well as the unilateral American raid into the country that killed Al Qaeda leader Osama bin Laden. Pakistan has since shut its border for NATO transits into Afghanistan.

More than a decade of Pakistani anti-terrorist operations by a majority Punjabi army in the predominantly Pashtun border area have pushed the Muslim nation onto the brink of civil war. The army’s offensives in the region displaced nearly half a million people.

Before the Afghan war escalated, the battle was confined to the tribal areas but since 2008, it has spread into Pakistan proper with bombings and assassinations taking place in major cities including Islamabad, Karachi and Lahore.