Western nations including the US, Australia, New Zealand, Germany, France and the UK have expressed concern over reported killings and disappearances of former members of the Afghan security forces after the Taliban took power.
In a joint statement issued over the weekend, the 21 countries plus the European Union referred to reports of such abuses documented by Human Rights Watch and others.
"We underline that the alleged actions constitute serious human rights abuses and contradict the Taliban's announced amnesty," said the statement, issued by the German Foreign Ministry on Sunday.
"Reported cases must be investigated promptly and in a transparent manner, those responsible must be held accountable, and these steps must be clearly publicised as an immediate deterrent to further killings and disappearances," it said.
Taliban spokespeople could not immediately be reached for comment. The Taliban have declared a general amnesty on members of the former government and military and say they are against any acts of reprisal by individuals in their ranks.
Human Rights Watch said in a report on November 30 that Taliban forces in Afghanistan have executed or forcibly disappeared more than 100 former police and intelligence officers since taking over the country on August 15, despite the proclaimed amnesty.
The Taliban interior ministry has rejected the Human Rights Watch report but said it would arrest anyone who could be shown to have carried out violent reprisals against members of the former military.
The joint statement said, "We will continue to measure the Taliban by their actions".
The statement was issued by Australia, Belgium, Bulgaria, Canada, Denmark, the European Union, Finland, France, Germany, Japan, the Netherlands, New Zealand, North Macedonia, Poland, Portugal, Romania, Spain, Sweden, Switzerland, the United Kingdom, Ukraine and the United States.
Australian Associated Press