Turkish President Recep Tayyip Erdogan has voiced regret over the downing of a Russian military jet, saying his country is "truly saddened" by the incident and wishes it had not occurred.

It was the first expression of regret by the leader since Tuesday's incident, in which Turkish F-16 jets shot down the Russian plane on grounds that it had violated Turkey's airspace despite repeated warnings to change course.

The incident marked the first time in half a century that a Nato member had shot down a Russian plane, and it drew a harsh response from Moscow.

Erdogan said: "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."

Addressing supporters in the western city of Balikesir, he said neither country should allow the incident to escalate and take a destructive form that would lead to "saddening consequences".

He renewed a call for a meeting with Russian President Vladimir Putin in the sidelines of a climate conference in Paris this week, saying it would be an opportunity to overcome tensions.

"On Monday in Paris there will be an international climate summit, that can be a chance to repair our relations with Russia. Confrontation will not bring anyone happiness. As much as Russia is important for Turkey, Turkey is important for Russia," Erdogan said

Erdogan's friendly overture however, came after he again vigorously defended Turkey's action and criticised Russia for its operations in Syria.

"If we allow our sovereign rights to be violated... then the territory would no longer be our territory," he said.

Putin has denounced the Turkish action as a "treacherous stab in the back", and he insisted the plane was downed over Syrian territory in violation of international law. He has also refused to take telephone calls from Erdogan.

Putin's foreign affairs adviser Yuri Ushakov said the Kremlin has received Erdogan's request for a meeting, but he would not say whether one will take place.

Asked why Putin has not picked up the phone to respond to Erdogan's two calls, he said "we have seen that the Turkish side hasn't been ready to offer an elementary apology over the plane incident".

After the incident, Russia deployed long-range S-400 air defence missile systems to a Russian air base in Syria just 30 miles south of the border with Turkey to help protect Russian warplanes, and the Russian military warned it would shoot down any aerial target that would pose a potential threat to its planes.

Russia has since also restricted tourist travel, left Turkish trucks stranded at the border, confiscated large quantities of Turkish food imports and started preparing a raft of broader economic sanctions.

Before Erdogan's address yesterday, Turkey issued a travel warning urging its citizens to delay non-urgent and unnecessary travel to Russia.

Meanwhile Two Turkish journalists arrested last week over their reports about arms supplies to Syria urged the European Union not to compromise on human rights and freedoms to reach an agreement with Turkey to help stem flows of migrants to Europe.

European diplomats have been measured in their criticism of media freedom in Turkey and President Tayyip Erdogan's increasingly authoritarian rule, recognising the West needs Ankara's help on the migrant crisis and as an ally in the US.-led coalition against Islamic State (IS)

Writing from Silivri prison near Istanbul, Can Dundar, editor-in-chief of Cumhuriyet newspaper, which is left-wing, secular and often critical of the government, and senior editor Erdem Gul said in a letter to EU leaders they hope today's meeting results in a lasting solution, adding:

"We would also like to hope that your desire to end the crisis will not stand in the way of your sensitivity towards human rights, freedom of press and expression as fundamental values of the Western world."

A court on Thursday ordered the arrest of the two journalists over the publication of footage purporting to show the state intelligence agency helping send weapons to Syria.