WASHINGTON: In a blunt message, the US has warned Pakistan that it will not hesitate to act alone, when necessary, to disrupt and destroy terror networks as the country's powerful spy agency ISI was not acting against all terror groups operating on its soil."The problem is that there are forces within the Pakistani government — specifically in Pakistan 's Inter- Services Intelligence or ISI — that refuse to take similar steps against all the terrorist groups active in Pakistan, tolerating some groups -- or even worse," Adam Szubin, Acting Under Secretary on Countering the Financing of Terrorism, told a Washington audience."We continue to urge our partners in Pakistan to go after all terrorist networks operating in their country. We stand ready to help them. But there should be no doubt that while we remain committed to working with Pakistan to confront ongoing terrorist financing and operations, the US will not hesitate to act alone, when necessary, to disrupt and destroy these networks," Szubin warned.In his remarks at the Paul H Nitze School of Advanced International Studies, Szubin said at the same time, Pakistan has been — and remains — a critical counter-terrorism partner in many respects."Of course, Pakistanis are themselves often the victims of brutal terrorist attacks on schools , markets, and mosques, and the list unfortunately goes on. And in the face of such violence, Pakistan has in some ways pushed back," Szubin said."Pakistan has achieved success in its ongoing operations against traditional terrorist safe havens in northwest Pakistan. It has officially designated ISIL as a terrorist organization. And it has gone after the funding and operational capabilities of Tehrik-e-Taliban Pakistan, or TTP," he said.But the ISI problem of supporting terrorist groups continues, he said."This is a distinction we cannot stand for," Szubin asserted.The US has been saying that Pakistan has not yet placed adequate pressure on the Haqqani Network of militants to prevent them from plotting deadly cross-border attacks in war- torn Afghanistan.Afghan authorities allege leaders of the Haqqani group, which is fighting alongside the Taliban , are directing high- profile attacks, particularly in the capital, Kabul, from their sanctuaries on Pakistani soil, with the covert support of the country's intelligence operatives.There is not adequate pressure being put on the Haqqanis" by the Pakistan government, The commander of US and NATO forces in Afghanistan, General John Nicholson had said last month."The Haqqanis operationally have been able to continue to conduct operations inside Afghanistan. They constitute the primary threat to Americans, to coalition members and to Afghans, especially in and around Kabul," he said.Pakistani authorities routinely deny the presence of any sanctuaries and insist counter-terrorism military operations have targeted and uprooted all militant infrastructures on their side of the border.