On Saturday, DVIDS said on Twitter that an employee of its DVIDSHub account posted a tweet that "in NO WAY supports the stance of the Department of Defense. It was inappropriate and we apologize for this mistake."
The decision to end the assessments, which have been produced in various forms since at least 2010, was published in the latest quarterly report by the US special inspector general for Afghanistan reconstruction.
The United States and Turkey remain at loggerheads over Ankara's plan to buy the air defense system from Russia, which Washington believes would compromise the security of its F-35 fighter jets, made by Lockheed Martin Corp.
The military did not say where the incident occurred but it came hours after a local Syrian official said that a roadside bomb has exploded in the tense, mixed Arab-Kurdish town of Manbij that is not far from the border with Turkey.
The Pentagon announced earlier this year a record total of 6,172 sexual assault reports in 2016, compared with 6,082 the previous year. This was a sharp increase from 2012, when 3,604 cases were reported.
IS has risen to prominence in the country's civil war targeting both army recruits of the government and Shiites, which it considers heretics. The group's last major attack was a suicide bombing in the government stronghold of Aden last December, which killed 48 soldiers.