"The time has come to embrace a strategy that dramatically increase the cost to Pakistan of its current approach," the diplomat said

A former top American diplomat - who served as the US envoy to Afghanistan, Iraq and the UN - today suggested a series of steps against Pakistan including slapping sanctions against the spy agency ISI and unilateral strikes inside its territory to end Islamabad's double game.

Afghan-born Zalmay Khalilzad who has emerged as one of the vocal critic of Pakistan and has accused it of being a state sponsor of terrorism made the remarks ahead of the announcement of White House actions to pressurise Pakistan.

In an op-ed in National Interest magazine, he recommended taking a series of steps against Pakistan to end its double game including slapping sanctions against ISI and individuals who are involved in supporting insurgents and terrorists; and undertake unilateral strikes inside Pakistani territory.

"Prepare to designate Pakistan as a state sponsor of terrorism unless it changes course and abandons support for terrorists. Such a designation will impose ongoing restrictions to assistance, bans on defense exports and sales, limitations on exports of dual use items, and other financial restrictions," Khalilzad said.

The former diplomat who hosted Trump as the candidate for his first major foreign policy speech called for suspension of economic assistance to Pakistan, holding Pakistan accountable before regional and international organizations in association with India and Afghanistan.

He also suggested reaching out to the people of Pakistan and document its support for terrorists and extremists.

"Patience, positive incentives, and occasional feeble pressure have not induced Pakistan to end its double game. Yet, success against terrorism and extremism in Afghanistan and the region requires a change in Pakistan's policy of support for such groups," he said.

"To bring about such a change, the time has come to embrace a strategy that dramatically increase the cost to Pakistan of its current approach," Khalilzad said.

A day earlier, the White House had said it would announce specific actions against Pakistan this week to force it to crackdown on terrorists on its soil, reflecting president Donald Trump's tough stance against over the issue.

The remarks by White House Press Secretary Sarah Sanders came after Trump accused Pakistan of giving nothing to the US but "lies and deceit" and providing "safe haven" to terrorists in return for $33 billion aid over the last 15 years.