Reports say Turkey shot down an unidentified drone near the country's border with Syria on Friday.

"Today, in our country's airspace near the Syrian border, an unknown aircraft was detected. Though warned three times, it continued its flight. After this, our border patrol planes, following rules of engagement, opened fire and shot down the aircraft," Turkey's General Staff said in a statement, according to Sputnik International.

The Washington Post reports Russia has denied any of its aircraft has been hit. However, an anonymous U.S. official believes that the downed drone was from the Russian military.

The aircraft wreckage was found and examined two miles beyond the Turkish border.

In the past few years, there have been numerous instances of Turkey shooting down Syrian aircraft operating in or near Turkish airspace. The country tightened its defense after Syrian ground fire brought down a Turkish fighter jet in 2012.

Turkey is a member of NATO, which supports the rebel resistance against Syrian President Bashar al-Assad's regime and the fight against ISIS. Russia's military presence in Syria has raised accusations that the country is seeking to support Assad in his fight against the rebels.

NATO has warned Russia to avoid entering Turkish airspace. A Russian military delegation met with Turkish officials in Ankara on Thursday, apologizing for the incursions.

Russian Ministry Defense spokesperson Maj. Gen. Igor Konashenkov claimed no Russian aircraft had been attacked in Turkey.

"All the airplanes of the Russian aviation group in the Syrian Arab Republic have returned . . . after accomplishing their combat tasks," he said in Moscow.

The U.S., who is leading an anti-ISIS coalition in Syria, has raised concerns about sharing airspace with Russian military. There is also the worry that Russia is preparing to send ground troops to the country in an effort to keep Assad in power.

U.S. officials also called the Russian incursions into Turkish airspace a deliberate provocation.

"I don't believe this was an accident. This is exactly the type of unprofessional, non-professional incident we were hoping to avoid," an anonymous U.S. defense official said.