Istanbul/Moscow
Turkish President Tayyip Erdogan warned Moscow not to "play with fire" on Friday, citing reports Turkish businessmen had been detained in Russia, while Moscow responded with tighter visa regulations.
Relations between the former Cold War antagonists are at their lowest in recent memory after Turkey shot down a Russian jet near the Syrian border on Tuesday. Russia has threatened economic retaliation, a response Erdogan has dismissed as emotional and indecorous.
The incident has proved a distraction for the West, which is looking to build support for the U.S.-led fight against Islamic State in Syria. The nearly five-year-old Syrian civil war has been complicated by Russian air strikes in defence of President Bashar al-Assad.
Turkey, which has long sought Assad's ouster, has extensive trade ties with Moscow, which could come under strain. Erdogan condemned reports that some Turkish businessmen had been detained for visa irregularities while attending a trade fair in Russia.
"It is playing with fire to go as far as mistreating our citizens who have gone to Russia," Erdogan told supporters during a speech in Bayburt, in northeast Turkey. "We really attach a lot of importance to our relations with Russia... We don't want these relations to suffer harm in any way."
He said he may speak with Russian President Vladimir Putin at a climate summit in Paris next week. Putin has so far refused to contact Erdogan because Ankara does not want to apologise for the downing of the jet, a Putin aide said.
Erdogan has said Turkey deserves an apology because its air space was violated.
Russian Foreign Minister Sergei Lavrov said on Friday Moscow would suspend its visa-free regime with Turkey as of January 1, which could affect Turkey's tourism industry.
Turkey's seaside resorts are among the most popular holiday destinations for Russians, who make up Turkey's largest number of tourist arrivals after Germany.
Russia's agriculture ministry has already has increased checks on food and agriculture imports from Turkey, in one of the first public moves to curb trade.
Erdogan said that Turkey did not go looking to shoot down a Russian jet, but acted after it strayed into Turkish air space. It was, he said, an "automatic reaction" to standing instructions given to the military.
Moscow insists the jet never left Syrian air space.
Lower house speaker Sergei Naryshkin called the incident an "intentional murder" of its soldiers, saying Russia had the right to mount a military response.
