WASHINGTON: The US said that it will work with Turkey and other international partners to hold Syria's Assad regime responsible for shooting down a Turkish Federal-4 fighter jet on June 22.

"We will work with Turkey, and other partners to hold the Assad regime accountable," White House Press Secretary Jay Carney said, ahead of Turkey taking up the issue before the North Atlantic Council on Tuesday.

"I am not going to characterise the outcome of a presentation the Turks will make. We obviously support the Turks and we will work with them. Turkey is a key ally of the US, member of NATO," Carney said, adding that the US was in close contact with the Turkish officials probing the matter.

Expressing US support to Istanbul, Carney said Washington "stood in solitary" with its "key" ally, looking forward to its presentation at the North Atlantic Council.

Turkey has asked for Article 4 consultation at NATO, which deals with any security related concern of the member nations.

Meanwhile, the State Department spokesperson Victoria Nuland has said that Washington initially would first be in the "listening mode" to Turkey to get a "better sense" of the path forward from their perspective, and then it will "go from there".

"There was no warning to this aircraft. It was just shot out of the sky. That obviously is not in keeping with international norms in such incidents," she said, accusing the Bashar al-Assad regime in Syria.

Reacting to reports that around 38 soldiers, including military officers, of Syrian military defected to Turkey overnight with their families, Nuland said the US has seen the reports and they appear to be "credible".

"So this appears to be an increasing pace of these kinds of military folks voting with their feet, voting with their airplanes, voting with their cars, voting with their families against the Assad regime," she said, pointing out that the US always wanted people to "follow their consciences, refuse orders and make their views clear".