ISTANBUL — NATO member Turkey shot down a Russian warplane a "matter of seconds" after it violated the country's airspace near the Syrian border on Tuesday, U.S. defense officials told NBC News.

"They were in Turkish airspace only 2 to 3 seconds, a matter of seconds" before the Turkish F-16s attacked, the officials said.

Russian warplanes had been launching airstrikes against Turkomen forces inside Syria for for the "past couple days," they said.

Those attacks "got the attention of the Turkish government and military," a senior defense official told NBC News. That official stopped short of saying the Turks shot down the Russian plane as payback for attacking their allies inside Syria.

The Turkish Air Force contends they warned the Russian aircraft 10 times over a span of 5 minutes before their jets opened fire. Visibly furious, Russian President Vladimir Putin responded to the Turkish version of events by calling the incident a “stab in the back by terrorist helpers.”

The area where the Russian jet was shot down is at the southern tip of Turkish territory to the west of the Syrian town of Bidama.

A U.S. military spokesperson in Baghdad backed the Turkish claim that they warned the Russian pilots they were in Turkish airspace before shooting down the aircraft.

“I can confirm that, yes,” Col. Steve Warren told a briefing but could not say whether the incursion was deliberate.

A still image from a video shows the burning trail of a plane coming down near the Turkish-Syrian border on Tuesday, according to HaberTurk TV Channel. HaberTurk TV / EPA

He added that the U.S. did not observe the shoot down, but heard what transpired because the aircraft were operating on open channels.

Two crew members ejected from the plane and one was shot and killed as he parachuted to the ground, Russian officials said — adding that a member of their search and rescue crew was also killed when their helicopter was hit by small arms fire.

It was the first time a NATO member downed a Russian or Soviet military aircraft since the 1950s, Reuters reported. And it risked worsening tensions between Moscow and the West.

"The Defense Ministry considers actions of the Turkish Air Force as an unfriendly act," the Russian Defense Ministry said in a statement, adding that Turkey's defense attache in Moscow has been handed an official protest.

NATO said it would meet later Tuesday to discuss the incident at the request of Turkish officials.

Footage from Turkish Haberturk TV showed a warplane going down in flames in a wooded area with a long plume of smoke trailing behind it.

Syrian fighters on the ground and Turkish sources told NBC News the Russian pilots ejected and landed north of Latakia, Syria. That area is controlled by rebels fighting to topple Syrian President Bashar Assad. Russia has an air base in Latakia which is used to launch bombing raids targeting Assad's foes — including ISIS.

A spokesman for the rebels in the area told NBC News that some of its fighters had opened fire on the pilots as they fell to the ground, killing one of them. The body was being held by the rebels, said the commander Jahid Ahmed, who added that he had no information on the second pilot.

A file photo of a Su-24 fighter jet taking off near Latakia, Syria. Russia's Defence Ministry / Reuters

The Russians have launched thousands of bombing raids in Syria since Sept. 30 when the Kremlin announced it would start targeting ISIS. Moscow stepped up the airstrikes after ISIS claimed responsibility for downing a Russian passenger plane.

However, U.S. officials have accused the Russians of targeting anti-Assad rebel groups as well.

Ian Shields, a professor of international relations at Anglia Ruskin University, warned the Turkish downing of the Russian warplane has the potential to spark a new Cold War.

Shields, a former Royal Air Force Group Captain, pinned much of the blame on the Kremlin, which he said had repeatedly violated Turkish airspace.

“Radar trace that I have seen is that the Russian aircraft was in Turkish airspace,” Shields said. “This is now moving it away from a spat between Turkey and Russia to a spat between NATO and Russia … this is, if you like, the escalation of tensions by diplomatic means.”