"Pakistan`s selective counter-insurgency operations, passive acceptance-and in some cases provision- of insurgent safe havens, and unwillingness to interdict material such as IED components, continue to undermine security in Afghanistan and threaten ISAF`s (International Security Assistance Force`s) campaign," the Pentagon said.
In a 138-page six-monthly report to the US Congress on the progress being made in Afghanistan in the war against terror, it acknowledged that there is strain in the relationship with Islamabad.
Overall, Pakistan continues to seek a government in Afghanistan friendly to it with limited Indian influence, and a political settlement that enables pro-Pakistani Pashtun power brokers to participate in provincial and national government, it said.
In its first report on Afghanistan sent to the Congress after Leon Panetta took over as Defence Secretary, the Pentagon said Pakistan continues to tolerate and abet the insurgency in Afghanistan, particularly the Haqqani network.
"Enabled by safe havens inside Pakistan, the insurgency remains resilient with a notable operational capacity, as reflected in isolated high-profile attacks in Kabul and sustained violence levels in eastern Afghanistan," the report said.
Though recent meetings between Afghan and Pakistani officials continue to seek common ground of cooperation in the aftermath of US withdrawal, the Pentagon said, however, mistrust, long-standing tensions and divergent strategic interest will continue to make genuine cooperation between Afghanistan and Pakistan difficult.
"Pakistan has long judged that the United States would withdraw from Afghanistan before achieving political stability, leaving Pakistan with either an unstable Afghanistan or an Indian `proxy` on its borders. Nor does Islamabad see a sustained US presence in Afghanistan as a preferable alternative over the long term," the report said.
"As a result, Pakistan seeks to play a dominant role in the peace and reconciliation process. However, early trends suggests that Pakistan is not prepared to deliver on the expectations established in bilateral and multilateral discussions on reconciliation," the Pentagon said.
Pakistan does not want to undermine its influence in a post-US withdrawal scenario by advancing negotiations on terms that are not assured to protect its interest, said the Pentagon report.
As a result of its shared border with Afghanistan, its status as a nuclear power, and its role as a partner in the shared fight against al-Qaeda and violent extremism, Pakistan remains a state of central importance in South Asia, it noted.