James Jeffery said during a hearing session in the US House of Representatives, "We have not seen common evidence of ethnic cleansing by Turkey."
The US official said, "But there are reports of numerous incidents of what are considered war crimes."
He added that US officials were looking into these reports and demanded an explanation from the Turkish government. He also said US officials were investigating a report that Turkey had used the banned burning white phosphorus during its attack, according to Reuters.
This came on the second day in a row during which Jeffrey and Matthew Palmer, the deputy assistant of the US secretary of state who handles files, including relations with Turkey, testify before the US Congress.