Turkish President Recep Tayyip Erdogan has expressed regret over the Turkish Air Force's downing of a Russian fighter jet near the country's border with war-torn Syria.

"We are truly saddened by this incident. We wish it hadn't happened as such, but unfortunately such a thing has happened. I hope that something like this doesn't occur again," the Turkish leader said Saturday, according to the Associated Press.

Erdogan's remark comes on a day when Russian President Vladimir Putin signed a decree ordering economic sanctions against Turkey over the incident.

"Nobody has the right to traitorously shoot down a Russian plane from behind. The president is mobilized, fully mobilized, mobilized to the extent that circumstances demand," Putin's spokesman Dmitry Peskov said Saturday while pointing out the need for retaliatory economic sanctions against Turkey, Haaretz reported.

"The circumstances are unprecedented. The gauntlet thrown down to Russia is unprecedented. So naturally the reaction is in line with this threat," he added. Russia has already suspended its visa-free agreement with Turkey.

The downing of the Su-24M fighter jet by the Turkish air force on Tuesday has heightened tensions between the two countries, as HNGN previously reported. Turkey continues to maintained that it's air force shot down the plane because it had violated the Turkish airspace. Moscow dismissed Turkey's explanation, saying that the fighter jet was downed in the Syrian airspace.