Taliban delegation met US special representative for Afghanistan Zalmay Khalilzad (File image)

A Taliban delegation met U.S. special representative for Afghanistan Zalmay Khalilzad on Thursday, two sources told Reuters, the first known contact between the two sides since U.S. President Donald Trump called off talks last month.

Trump halted the talks, which aimed at a plan to withdraw U.S. troops from Afghanistan in exchange for Taliban security guarantees, following the death of a U.S. soldier and 11 others in a Taliban bomb attack in Kabul.

However, the sources cautioned that the meeting in Pakistan's capital of Islamabad, which ran more than an hour, did not represent a resumption of formal negotiations.

"The Taliban officials held a meeting with Zalmay Khalilzad...all I can tell you is that Pakistan played a big role in it to convince them how important it was for the peace process," a senior Pakistan official told Reuters, but declined to be identified as he was not authorized to speak publicly.

He added that the meeting, which was confirmed by a second source, did not involve formal negotiations on the peace process, but aimed at building confidence. He declined to elaborate further on the discussions.

The U.S. embassy in Islamabad and the State Department in Washington declined to comment on whether there had been a meeting.

A State Department representative said Khalilzad had spent several days in Islamabad this week for consultations with authorities in Pakistan, but his meetings in Islamabad did not represent a restart of the Afghan peace process.

Zabihullah Mujahid, a Taliban spokesman, would not confirm or deny that Taliban had met Khalilzad, adding that the Taliban delegation was still in Islamabad for meetings on Friday.

Speaking on condition of anonymity, a Taliban leader in Afghanistan said the delegation's visit to Pakistan was intended to revive negotiations and end the 18-year war.

A spokesman for Pakistan's foreign office did not immediately respond to a request for comment.

The U.S. government told Kabul that Khalilzad planned to meet the Taliban in Islamabad, a senior Afghan government source said.

However, Afghan officials were told the meeting was to discuss the 2016 kidnapping of two university professors, American Kevin King and Australian Timothy Weeks, in Kabul by the Taliban-affiliated Haqqani group.

The source said the Afghan government, led by President Ashraf Ghani, does not want the peace process to resume unless it is led by Afghans. Ghani has complained bitterly about the Taliban shutting his administration out of the previous talks.

The Taliban delegation led by Mullah Abdul Ghani Baradar, one of the group's founders, met Pakistan's foreign minister in Islamabad on Thursday and both sides called for a resumption of the talks as soon as possible.

Video of Pakistan's warm welcome for the Taliban this week circulated on media sites, and Afghans bristled on social media at images of Taliban and Pakistan officials exchanging hugs and smiles.

The United States has long considered Pakistan's cooperation crucial to ending the war in Afghanistan.

The latest developments follow a meeting last week between Trump and Pakistan Prime Minister Imran Khan on the sidelines of the United Nations General Assembly in New York.

The United States and Taliban said last month, shortly before talks broke off, that they were close to reaching a deal, despite concerns among some U.S. security officials and in the Afghan government that a U.S. withdrawal could bring more conflict and a resurgence of Islamist militant factions.