Nato is holding an emergency meeting in Brussels to discuss Turkey’s military campaign against the Islamic State (IS) group and Kurdish militants.
Turkey was until recently a reluctant partner in the US coalition against IS, but over the past few days it has bombed IS and Kurdish positions.
Turkey is also backing plans for a buffer zone on the border with Syria.
Turkey’s prime minister said he expects his country’s allies to show solidarity and support for its campaign.
Meanwhile Turkish police have continued to arrest suspected members of IS, the PKK and leftist groups – more than 1,000 over the past week.
The US and Turkey are working together on plans to create an “IS-free zone” along the border with Syria.
As well as targeting IS militants, the zone would also allow Turkey to hit positions held by the outlawed Kurdish PKK group.
Turkey says it draws no distinction between the PKK and IS, considering them both terrorist organisations.
Turkish President Recep Tayyip Erdogan said the creation of a “safe zone” would pave the way for the return of Syrian refugees.
Turkey is struggling with more than 1.8 million refugees from the Syrian conflict.
Under the plan, militants would be removed from a 68-mile (109km) stretch west of the Euphrates River, officials say.
Such a deal would significantly increase the scope of the US-led air war against IS in northern Syria, say analysts.
The crisis has exacerbated tensions in a part of Turkey where a conflict between the outlawed PKK and government troops has killed about 40,000 people since 1984.
Last week Turkey agreed to allow the US to use its air base at Incirlik to launch air strikes against IS.
Turkey called the meeting of ambassadors to Nato under a clause allowing members to request a summit if their territorial integrity or security is threatened.
It is only the fifth such request in the alliance’s history.
Nato Secretary General Jens Stoltenberg said as he arrived for the talks: “Terrorism in all its forms can never be tolerated or justified.
“It is right and timely that we hold this meeting today to address the instability on Turkey’s doorstep and on Nato’s border.”
‘Outside the scope’
Turkey’s cross-border strikes followed a wave of attacks by militants on Turkish soil.
In the worst incident, IS-linked militants killed 32 people in the Kurdish-majority town of Suruc, near the Syrian border on 20 July.