( CNN ) A U.S. Army soldier was killed Wednesday in an attack in eastern Afghanistan by an Afghan National Army gunman , a U.S. military official told CNN , shortly after an American official met with a provincial governor . A U.S. defense official did n't provide details about the attack in the city of Jalalabad . But an Afghan police chief told CNN that an Afghan National Army soldier shot at U.S. soldiers at a provincial governor 's compound in Jalalabad on Wednesday . The Afghan soldier opened fire on the U.S. troops as they were leaving a meeting at the compound , said Fazal Ahmad Shirzad , police chief of Nangarhar province . An Afghan soldier was killed and another was injured in a subsequent exchange of gunfire , Shirzad said . It was n't immediately clear whether the assailant was among them . A senior U.S. official had just held a meeting with Nangarhar 's governor at the compound when gunfire erupted , a U.S. Embassy representative said . The embassy representative did n't identify the official but said that all diplomatic personnel had been accounted for after the incident . The U.S. military official did n't know yet what motivated the shooting . Other troops were injured in the attack , the U.S. defense official said , speaking on condition of anonymity . Those troops belong to the NATO-led Resolute Support mission meant to train and support Afghan troops . The defense official did not provide the nationalities of the injured Resolute Support troops . Most of the troops involved with Resolute Support are with the U.S. military . CNN national security analyst Peter Bergen said that despite Wednesday 's incident , instances of `` green-on-blue '' attacks are declining overall for several reasons . `` First , there are far fewer US soldiers in Afghanistan , '' Bergen said . `` Second more counterintelligence resources were devoted to countering the threat and third , an attempt was made to better vet afghan army recruits . '' CNN 's Masoud Popalzai and Jim Sciutto contributed to this report from Kabul , Afghanistan .
Gunfire erupts after senior U.S. official meets with Afghan governor in Jalalabad , Afghan National Army says . Afghan soldier fires at U.S. troops , Afghan police official says .