An attack on one of the only women to take part in negotiations with the Taliban was a “cowardly and criminal” attempt to disrupt the Afghan peace process, the US envoy said.
Zalmay Khalilzad said he was “relieved” that Fawzia Koofi escaped the shots on Friday “without serious injury”.
Ms Koofi was shot in the right arm while traveling with her sister.
The Taliban denied being the cause of the attack, which took place as the two sides prepared for talks.
The militant group has previously refused to negotiate directly with the Afghan government, but agreed to participate in talks aimed at ending nearly two decades of conflict after reaching a deal with the United States in February.
As part of this agreement, the Afghan government had to release 5,000 Taliban prisoners. On Thursday, he began to release the last 400 activists. Talks are expected to begin in Qatar after the release of the last prisoner.
- Fawzia Koofi: the woman who negotiated with the Taliban
- ‘We can’t go back’: Afghan women determined not to lose
But there are fears that the attack on Ms. Koofi, a staunch Taliban critic who was returning from a meeting in northern Parwan province when it was attacked near the capital Kabul, could undermine the process.
“A worrying pattern of targeted attacks that can negatively impact confidence in the peace process,” Afghanistan Independent Human Rights Commission chief Shaharzad Akbar wrote on Twitter.
Khalizad also took to Twitter, saying he wanted “all peace-seeking parties not only to condemn the attack, but to speed up the peace process and start intra-Afghan negotiations as soon as possible.”
The attack, which no one claimed, was also condemned as “cowardly” by President Ashraf Ghani and Abdullah Abdullah, the head of the High Council for National Reconciliation.
Ms Koofi is one of the few women to have taken part in the dialogue with the extremist Islamist group, which ruled Afghanistan until they were removed from power in Afghanistan by a US-led invasion in 2001 .
They have fought to regain territory ever since. Last year alone, more than 3,000 civilians were killed in the conflict, according to United Nations figures.
However, the deal reached with the United States proved controversial. On Saturday, France opposed the release of some of the 400 remaining prisoners held by Afghan authorities – some of whom were believed to have been implicated in the killings of French nationals.