Turkish President Abdullah Gul said on Saturday it was not possible to ignore the fact that Syria had shot down a Turkish fighter jet and said everything that needed to be done following the incident would be done, Turkish media reported.

"It is not possible to cover over a thing like this, whatever is necessary will be done," Gul was quoted as saying by state news agency Anatolia. It was not immediately clear where he was speaking.

Gul said it was routine for jets travelling at high speed to cross borders for a short distance. He said an investigation into the incident would look at whether the plane was downed in Turkish airspace, media reported.

Gul also said Ankara had been in telephone contact with Damascus and that a search operation for the plane and missing pilots was still under way.