President Obama called the Doctors Without Borders chief and the president of Afghanistan to apologize for the airstrike on a hospital in Kunduz, Afghanistan, White House Press Secretary Josh Earnest said Wednesday.
The president spoke by telephone with Doctors Without Borders International President Dr. Joanne Liu, to apologize and express his condolences for the organization's staff and patients who were killed and injured when a U.S. military airstrike mistakenly struck a field hospital in Kunduz, Afghanistan over the weekend, Earnest told reporters during the White House press briefing.
The president promised a full investigation of the incident. In addition to a Department of Defense investigative process that is already underway, there also will be an investigation that is conducted by NATO and a third joint investigation carried out by U.S. military personnel alongside Afghan security officials into the deadly airstrike.
Doctors Without Borders Doctors renewed its call on Wednesday for an unprecedented international and independent humanitarian fact-finding commission.
"We received President Obama's apology today for the attack against our trauma hospital in Afghanistan," Liu said in a statement. "However, we reiterate our ask that the U.S. government consent to an independent investigation led by the International Humanitarian Fact-Finding Commission to establish what happened in Kunduz, how it happened, and why it happened."
The president also spoke with Afghan President Ashraf Ghani to "express his condolences for the innocent loss of life in that incident," Earnest said.
Twelve Doctors Without Borders staff along with seven patients, including three children, were killed after the airstrike hit the international charity's hospital in the Afghan city of Kunduz.
Another 37 others were injured in the strike: 19 staff members, including five in critical condition, and 18 patients and caretakers.
"This was not just an attack on our hospital, it was an attack on the Geneva conventions," Liu said earlier on Wednesday. "This cannot be tolerated."
Doctors Without Borders said it sent letters to 76 countries that have signed Article 90 of the additional protocol to the Geneva Conventions, seeking to mobilize the commission.
The United States and Afghanistan — which are not signatories — would also have to give their consent to such a mission. Doctors Without Borders says it has had no response yet from any of the countries.
The White House stressed on Wednesday that there are specific and technical parameters of meeting the criteria of a war crime, but acknowledged that the airstrike was a tragic "mistake."
The Pentagon has said American forces were not under direct fire when local Afghan forces asked for air support just prior to the U.S. bombardment of the hospital. Gen. John Campbell, the top U.S. commander in Afghanistan, said Tuesday that U.S. Special Operations Forces "were in close vicinity" to the Doctors Without Borders hospital in Afghanistan and were "talking to the aircraft" that launched the airstrikes.
This article originally appeared on NBCNews.com.