United States President Barack Obama in a phone call on Wednesday apologized to Médecins Sans Frontières (MSF) chief Joanne Liu for the Kunduz hospital airstrike.
Obama said that the strike was a mistake and promised that those who are responsible for the attack will be accountable.
But the MSF chief, who condemned the airstrike as a war crime, insisted on an independent investigation.
Liu said that if the Kunduz hospital airstrike is ignored and if safe medical environments are not provided for medical workers, aid agencies will not be able to work in places like Syria, South Sudan or Yemen.
Meanwhile the White House has also broached the possibility of compensation to victims.
The airstrike occurred in the early hours of Saturday morning killing 22 people, including 12 MSF staff members.
MSF officials have blamed the United States.
In addition, U.S defense secretary Ashton Carter, earlier this week, expressed his deep condolences and sympathy to the Afghan families who lost their loved ones in the incident.
Carter said the Pentagon is currently busy with a transparent and complete investigation of the strike and will share the findings with the people.
The Pentagon is committed to finding the facts, he said.
On Tuesday the American commander of international forces Gen. John Campbell said that the Kunduz airstrike against the hospital was a mistake.