The men were arrested in the Qarghayi district of northeastern Laghman province on Sunday, just 150 feet from where Khalilzad had planned to inaugurate a road along with Afghanistan’s interior minister, chief presidential spokesman Jawed Ludin told The Associated Press.
Two senior Afghan officials said the men had confessed to their crimes and said they were in Afghanistan “to fight jihad.”
“Their aim was to assassinate Khalilzad, and they came to Afghanistan specifically for this operation,” said one of the officials.
Afghan television later broadcast a video of the suspects in custody. The men, all young and with thin moustaches, are seen sitting together on a brown sofa being questioned by a man off camera. They identified themselves as Murat Khan, Noor Alam, and Zahid and say they are from Pakistan. None confessed on camera or were asked any questions about the attack.
The US Embassy in Kabul had no immediate comment on the assassination plot, but said it would release a statement later.
Mr Khalilzad, who is to be the next American ambassador in Iraq, cancelled his appearance at the road opening at the last minute and was never in danger, the official said. Interior Minister Ali Ahmad Jalali also cancelled his appearance.
The official said the fact the plotters knew of Mr Khalilzad’s trip, and that Jalali was to be with him, was “very disturbing”.
It was not clear who had sent the men. One of the officials said the Afghan government was extremely angry at what he called a “lack of co-operation” from Islamabad in stopping militants crossing the border.
He said Pakistan’s lack of resolve was a factor in both the assassination plot, and a recent upsurge in violence across southern Afghanistan that has left hundreds dead.
Pakistani Information Minister Sheikh Rashid Ahmed reacted angrily to any hint of official sanction for the attack.
“This is a baseless allegation,” he told AP.
“Pakistan is not involved in any such thing now or in the past.”