Washington: In a stern message to Pakistan, the United States has asked it to shed its policy of “using insurgents” like LeT as a strategic tool and warned that if it cannot deliver against terrorists, the US may be impelled to use “any means” at its disposal.

The message, which has been conveyed in a letter from US President Barack Obama to his Pakistani counterpart Asif Ali Zardari, also includes an offer by him to try to “reduce tensions” between India and Pakistan, media reported here.

The two-page letter, hand-delivered by national security adviser general (retd) James Jones when he visited Islamabad early this month, offers Pakistan enhancement of strategic partnership if they act as wished by the US, besides additional military and economic aid.

In his letter, Obama has also warned Pakistan that its use of insurgent groups for policy goals “cannot continue” and called for closer collaboration against all extremist groups.

He named five such groups - al-Qaeda, the Afghan Taliban, the Haqqani network, Lashkar-e-Taiba (LeT) and Tehrik-e-Taliban.

“Using vague diplomatic language, he said that ambiguity in Pakistan’s relationship with any of them could no longer be ignored,” the Washington Post reported.

Jones did some straight-talking with the top Pakistani leadership, the daily said. “If Pakistan cannot deliver, he warned, the US may be impelled to use any means at its disposal to rout insurgents based along Pakistan’s western and southern borders with Afghanistan.”