The U.S. has been engaging with the Taliban, but so far they have refused to talk directly to the Afghan government, which it sees as a puppet. Afghans are wary of Pakistan's involvement in crafting a future for their country, but Khan said the Taliban need to participate in the next Afghan presidential election in September.
"It's not easy. It's not going to be easy," Khan said about getting the Taliban and the Afghan government to the negotiating table.
Khan said the Taliban delegation to the U.S. negotiations asked to meet with him a few months ago probably because the prime minister has maintained there is no military solution to the war in Afghanistan. He said at the time that he didn't do it because the Afghan government didn't want him meeting with the Taliban.
But Khan said he's spoken with Afghan President Ashraf Ghani and he will reach out to the militant group when he returns to Pakistan. He met Monday with President Donald Trump.
"Now, I will meet the Taliban and I will try my best to get them to talk to the Afghan government," Khan said at the U.S. Institute of Peace in Washington. "The election in Afghanistan must be an inclusive election where the Taliban are also participating."
With all the talk about peace negotiations, Afghans were stunned Monday when Trump said he could unleash the U.S. military and wipe Afghanistan off "the face of the earth" in a week or 10 days.
Trump's casual comments were viewed with alarm because the war has not been between the U.S. and Afghanistan. For years, Afghan security forces have fought alongside their U.S. and NATO partners against the Taliban.
Ghani's office in Kabul on Tuesday asked Trump to clarify his statement and said Afghanistan will never "allow any foreign power to determine its fate."
Afghans also are wary of statements coming from Pakistan. For years, they have accused Pakistan of creating instability in their country by giving militants a safe place from which to stage attacks across the two countries' long, porous border.
Washington also has blamed Pakistan for harboring the insurgency, making it impossible to defeat the militants, who now control roughly half of Afghanistan, but not the cities.
Khan insisted that Pakistan is changing.
"It is the intent of Pakistan that we do not allow any armed militias in our country," he said, acknowledging that they still reside in the country, but that the army was working to disarm them.
A senior administration official said the U.S. welcomes his pledge that Pakistan will not allow its soil to be used by militant groups, but said the administration was "clear-eyed" about the support that Pakistan's military and intelligence services have given to militant groups and will look for "concrete action." The official spoke only on condition of anonymity to brief reporters before Khan's visit.
Khan said his meeting with Trump went well and that he believes the U.S. and Pakistan are now "on the same page."
"We loved our meeting with President Trump yesterday," Khan said in a morning meeting with Secretary of State Mike Pompeo. "I told the president, I said 'I've been a public guy for 40 years, and so when you go meet someone who is high-profile you get a lot of advice,' Never have I gotten so much advice."
Warming relations would mark a turnaround for Khan and Trump, who has been sharply critical of Pakistan. The Obama administration increased military and economic aid to around $3 billion a year, but Trump cut it to about $70 million in the current fiscal year, saying the U.S. was sending money to Pakistan, but was getting only "lies' in return.
Khan said he didn't ask Trump to restore the aid, which he said had created a "dependency syndrome" in Pakistan. Khan said he wants Pakistan to have a "dignified" relationship with the U.S. based on "mutual trust." Khan said he never felt more humiliated than when the U.S. carried out the raid on al-Qaida leader Osama bin Laden's compound inside Pakistan without giving Islamabad a heads-up.
"Our ally didn't trust us," he said. "For every Pakistani, it was humiliating."