The former US special representative for Afghanistan reconciliation Zalmay Khalilzad said the US was losing the war to the Taliban, so it chose peace negotiations as an alternative.

Talking to CBS News, Khalilzad said the US military tried many times to strengthen its position on the battleground, but it failed. "The negotiation was a result of--based on the judgment that we weren't winning the war and therefore time was not on our side and better to make a deal sooner than later."

Khalilzad blamed the then-president Ashraf Ghani for the disintegration of Afghanistan's security sector, saying his escape triggered the chaos in the Afghan capital. He said the Taliban was in discussions with him about forming a power-sharing government and including some officials of the Ghani administration in the next government. All these things did not happen because Ghani did not stay, he said.

Khalilzad said Ghani did not want to let go of power and discredited Ghani's remarks about fleeing Kabul to avoid bloodshed, saying they were not true. "So, the question is, why did President Ghani do what he did? If he was willing to step aside for the sake of peace, imagine if he had offered that a year ago, six months ago -- that somebody that's mutually acceptable could have led the government. But he did not," he said.

According to Khalilzad, the US has succeeded mainly in suppressing Al Qaeda- the reason it went to Afghanistan--but has failed in building a democratic Afghanistan. He said the two decades of US involvement have transformed Afghanistan, and now "the Taliban are going to have a hard time putting them back in the box the way they had put people in the 1990s."

Khalilzad said the US wanted a different outcome for the Afghan peace talks, preferably a power-sharing government with the Taliban instead of August 15.

Khalilzad said the Taliban has lived up to its promise of cutting ties with terrorist groups and not allowing Afghanistan to be used for staging attacks against the US and its allies. "They are not allowing plotting and planning operations by Al-Qaeda against the United States," he said.