WASHINGTON - The United States has said that a UN report on possible war crimes in Yemen is "very concerning," calling on parties to the conflict to avoid violations. "We've seen that report from the Human Rights Council," State Department spokeswoman Heather Nauert told reporters, saying that possible violations of international law "as outlined in that report are very concerning to the US government." "We believe that if such crimes have taken place that there is simply no justification," she said, calling on parties to the conflict to "take necessary measures to prevent such violations."

On Tuesday, UN investigators said that all sides in Yemen's bloody conflict may have committed war crimes, highlighting deadly air strikes, rampant sexual violence and the recruitment of young children as soldiers. US Defense Secretary Jim Mattis on Tuesday strongly defended the US-backed Saudi-led coalition that is fighting against Iran-backed Huthi rebels in Yemen.

The coalition, whose air campaign has taken a heavy toll on civilians in the country, has rejected "inaccuracies" in the UN report and criticized its "non-neutrality."

But Mattis added that US support was "not unconditional," the conditions being that the coalition does "everything humanly possible to avoid any innocent loss of life, and they support the UN-brokered peace process."