The NATO-led International Security Assistance Force in Afghanistan also condemned the execution.
"Let's be clear, this wasn't justice, this was murder, and an atrocity of unspeakable cruelty," ISAF commander Gen. John Allen said in a statement Sunday. "The Taliban's continued brutality toward innocent civilians, particularly women, must be condemned in the strongest terms. There has been too much progress made by too many brave Afghans, especially on the part of women, for this kind of criminal behavior to be tolerated."
The public execution is the latest and among the most shocking examples of violence against women in Afghanistan, but it is far from an isolated case.
The Taliban also does not have a monopoly on the violence, cautioned Christine Fair, with the Center for Peace and Security Studies at Georgetown University.
"It's really important to not see this exclusively in terms of the Taliban, but this is a set of practices that actually have existed and continue to exist throughout Afghanistan," she said.
Nearly nine out of 10 women suffer physical, sexual, or psychological violence or forced marriage at least once in their lifetimes, Human Rights Watch said in its 2012 annual report.
The country has 14 shelters for abused women, a number which the campaign group says "does not meet even a small fraction of the need."
Hundreds of students and teachers at girls' schools in the country have been hospitalized with suspected poisoning this year alone. Girls were forbidden to go to school when the Taliban ruled the country from 1996 to 2001.
Salangi, the provincial governor, spoke to CNN about the killing on Sunday, the same day that representatives of more than 80 nations and organizations met to consider pouring billions more aid dollars into the country.
U.N. Secretary General Ban Ki-moon urged delegates including U.S. Secretary of State Hillary Clinton not to demand complex reforms in exchange for the money.
"Afghan institutions are still in their nascent stages," he said. "The very programs which offer the best hope of sustainability of Afghan institutions should not be held hostage to complex preconditions."
Clinton said donors at the conference pledged about $16 billion for Afghanistan over four years. That amount did not include money from the United States because any foreign aid must be approved by Congress.
Under a security pact with Afghanistan, nearly all U.S.-led NATO troops will withdraw from the country by the end of 2014.
"We can ask the question what will happen when we leave, but let's remember that this is actually happening while we're still there," said Fair, with Georgetown.