President Barack Obama has apologized to Doctors Without Borders for the U.S. bombing of the international medical charity's hospital that killed 22 people last weekend in Kunduz, Afghanistan.
White House spokesman Josh Earnest said Obama called the medical group's president, Joanne Liu, to "apologize and express condolences."
"In this case, there was a mistake and it's one that the U.S. owns up to," Earnest said. He said Obama "is very eager to get to the bottom of what exactly occurred."
Obama also called Afghan President Ashraf Ghani to express his condolences for the loss of lives in the bombardment Saturday, the spokesman said, and to commend Afghan forces for their bravery in the fight to control the northern Afghan city in clashes with Taliban insurgents.
Doctors Without Borders, known by the French acronym MSF, called Wednesday for an independent panel to investigate the incident under the Geneva Conventions.
"It is unacceptable that the bombing of a hospital and the killing of staff and patients can be dismissed as collateral damage or brushed aside as a mistake," Liu said before her conversation with Obama.
Liu said the facts of the attacks needed to be investigated impartially and independently, and that MSF could not rely on the internal probes being conducted by the U.S., Afghanistan and NATO.
MSF has suggested that the bombing could be considered a war crime, but Earnest said "no one has offered any evidence that it's anything but a terrible, tragic mistake."
U.S. Army General John Campbell, who heads the NATO-led coalition in Afghanistan, told a congressional committee Tuesday that U.S. forces were responsible for "mistakenly" hitting the hospital.
But MSF Switzerland General Director Bruno Jochum said the hospital was targeted "without doubt," with four or five strikes coming in less than an hour and none of the surrounding buildings being hit.
"We're not talking about the random bomb or the random bullet that basically creates damage in one of our facilities," he said. "We're talking about the methodic destruction of the main building of the hospital offering intensive care and trauma care to patients."
Jochum said the hospital's existence was known to everyone in the area and had been operating for four years. He highlighted the importance of investigating the attack, saying that allowing a country to get away with such an act sends a message "to all armed groups that this can happen."
Campbell told lawmakers that Afghan forces requested the airstrike on the MSF hospital because Taliban insurgents were firing from the facility, and that U.S. forces acted after reviewing the request.
"To be clear, the decision to provide aerial fire was a U.S. decision made within the U.S. chain of command," Campbell said. "A hospital was mistakenly struck. We would never intentionally target a protected medical facility."
Liu said the space in which humanitarians can operate in war zones is under threat. She said it would not be possible for Doctors Without Borders and other medical workers to continue their activities in countries such as Syria, South Sudan and Yemen if they were not protected.
“If we let this go as if it was a nonevent, we are basically giving a blank check to any country who is at war and conflict and telling them, ‘You know what, you can do whatever you want, because actually nothing is happening; you are not being held accountable for anything,' " she said.
When Obama ended American ground combat operations in Afghanistan last year, he said that the residual force of 9,800 U.S. troops remaining there should focus on training and advising Afghan troops. He limited the use of force to three circumstances: the defense of U.S. and allied troops, support for missions targeting remnants of al-Qaida insurgents in Afghanistan, and assisting Afghan troops facing mass casualties in extreme situations.
It is not clear whether the U.S. bombing of the hospital met any of those criteria.
Campbell said he had ordered American forces in Afghanistan to be retrained on their use of force.
"To prevent any future incidents of this nature," he said, "I've directed the entire force to undergo in-depth training in order to review all of our operational authorities and rules of engagement."
U.S. Defense Secretary Ash Carter said in a statement, "The U.S. military takes the greatest care in our operations to prevent the loss of innocent life, and when we make mistakes, we own up to them. That is exactly what we are doing right now. We will do everything we can to understand this tragic incident, learn from it, and hold people accountable as necessary."
Afghan forces have been trying for several days to regain full control of Kunduz in the northern part of the country after Taliban insurgents briefly seized it last week.