On the eve of her arrival, the deputy secretary of state, Wendy Sherman, used a public event in Mumbai to lay out in blunt terms the new parameters of US-Pakistan relations, stressing there would be no equivalence with Washington's deepening ties to India.

 

The Islamabad trip was for "a very specific and narrow purpose", Sherman said, to talk about Afghanistan and the Taliban, the report said.

 

"We don't see ourselves building a broad relationship with Pakistan, and we have no interest in returning to the days of hyphenated India-Pakistan," she added. "That's not where we are. That's not where we're going to be."

 

Sherman's reception in Pakistan the next day was stilted. A planned meeting with Prime Minister Imran Khan never materialised.

 

Senior Pakistan government officials told the Guardian that there was diplomatic tension between the two countries that needed to be resolved and that Khan was angry that he had still not received a phone call from Joe Biden, the report added.

 

The decision not to call is intended to be an unambiguous signal of Washington's displeasure with Imran Khan's attitude to Afghanistan.

 

The cold approach has come as a shock to Islamabad, which had been accustomed to Trump's informal and personal relationship with Khan.

 

In a recent leaked memo, the foreign minister, Shah Mahmood Qureshi, urged the Pakistani embassy in Washington to get a call arranged between Biden and Khan, the report said.

 

"In spite of the existing situation in Afghanistan, and the key role played by Pakistan, it is unfortunate that the White House remains indifferent to the Pakistani leadership," the letter said, blaming "the immature understanding of the White House staff".

 

"You are thus expected to take adequate measures, ensuring that enough diplomatic steps are taken to guarantee the strategic relevance of Pakistan in all diplomatic forums."

 

The foreign minister insisted the letter was a fake but official sources said it was authentic.

 

Pakistan has been long accused of playing a double game in the fight against terrorism, on one hand being a supposed ally in the US "war on terror" while also supporting and sponsoring the Taliban, and allowing them to live and regroup on Pakistan soil.

 

Cyril Almeida, a columnist and analyst, said: "Since 9/11, the US has seen Pakistan through an Afghan prism. Now that Pakistan is perceived to have won another proxy war against a superpower in Afghanistan, the superpower appears to be in no mood to forgive or forget."

 

"Pakistan is desperate to move on from the past and let bygones be bygones and wants to broaden out its relationship and focus on geo-economics, but from Washington's standpoint, Afghanistan is going to continue to dominate its interests in the region for the foreseeable future," Elizabeth Threlkeld, the director of the South Asia programme at the Stimson Center, said, the report added.

 

Since the Taliban came into power in mid-August, Pakistan has been publicly talking about the future recognition of the Taliban government, which has close ties to Pakistan's powerful military intelligence services, the ISI.

 

Zahid Hussain, the author of No-Win War: the Paradox of US-Pakistan Relations in Afghanistan's Shadow, said that relations were at their lowest ebb. "There is lack of hope that the relations will get better, as the things are not moving towards rapprochement between both countries. Today, we don't see the strategic relations between the US-Pakistan -- it is only a transactional relation now," he said, the report added.