Two Turkish soldiers have died after their helicopter was shot down during Ankara's military operation against Syrian Kurdish fighters in northern Syria.

Binali Yildirim, Turkey's prime minister, announced the deaths in a televised address on Saturday.

Earlier, Turkish President Recep Tayyip Erdogan had said an army helicopter had been "shot down" near the southern Hatay province.

"These things will happen, we are in a war ... We might lose a helicopter, but they'll pay the price for this," he said in Istanbul.

The state-run Anadolu Agency, citing the Turkish army, said the ATAK aircraft crashed at around 1pm local time (10:00 GMT).

Mustafa Bali, a spokesman for the Kurdish YPG armed group, told the AP news agency that his fighters downed the helicopter in Raju, northwest of the Syrian city of Afrin.

Turkey opened a new front in the multisided Syrian civil war, when it launched an air and ground offensive against YPG fighters on its southern border with Syria last month.

Armed campaign

The YPG - trained, armed and supported by the US to fight against the Islamic State of Iraq and the Levant (ISIL) - controls a swath of land in northern Syria.

Turkey considers the YPG an extension of the outlawed Kurdistan Workers Party (PKK), which has fought a decades-long armed campaign.

Against this backdrop, HR McMaster, the US national security adviser, held talks on Sunday with his Turkish counterpart, Ibrahim Kalin, in Istanbul.

According to a joint statement issued by the White House and Turkish presidency, they "addressed issues affecting bilateral relations in detail and explored ways to expand the joint fight against all forms of terrorism".

Rex Tillerson, US secretary of state, is also due to visit Ankara next week as part of a trip to five countries in the Middle East.

Al Jazeera's Jamal Elshayyal, reporting on Sunday from Gaziantep on the Turkey-Syria border, said the conflict was "escalating day by day".

More than 20 Turkish soldiers and 150 YPG fighters have been killed since the military offensive began, he said. Seven Turkish civilians have also lost their lives.