Turkey has started striking Islamic State militants, which helps the US-led coalition, but also began attacking Kurds.
The US has been relying on Kurds associated with the Kurdistan Workers' Party, or PKK, to make progress against IS.
White House spokesman Alistair Baskey is strongly condemning recent terrorist attacks by the PKK, which the US has designated a terrorist group. He's also pointing out that Turkey is a NATO ally of the US.
Baskey says the PKK should renounce terrorism and resume talks with Turkey's government. But he also says that both sides should avoid violence and pursue de-escalation.