Russia has warned of heavy economic sanctions after Turkey shot down a Russian warplane on its border with Syria.
Russia is Turkey’s second most important foreign trading partner after Germany.
As a result, experts say economic retaliation would be keenly felt by Ankara – but the Kremlin would not be unharmed either.
Here the BBC’s Russian Service looks at the main trade links between Russia and Turkey that risk being hit hardest by the downturn in relations.
Turkey is the top foreign holiday destination for Russian tourists. Some 3.2 million Russian holidaymakers travelled to Turkey last year, according to Russia’s Federal Tourism Agency. In comparison, 2.5 million went on holiday to Egypt.
Until the past year, Russians made up the largest group of tourists in Turkey. But they lost the top spot to Germans because of the fall of the rouble.
Bookings to Turkey went back up after Russia banned flights to Egypt following the Sinai plane crash on 31 October. However, the downing of the Russian SU-24 warplane by Turkey means it is unlikely this trend will continue.
Turkey bought 57% of its gas from Russia in 2013.
Last year it became the second largest consumer of Russian gas after Germany: Germany imported 36bn cubic metres (bcm) and Turkey imported 27.3bcm.
Turkey gets its Russian gas via two routes – the Blue Stream pipeline across the Black Sea, and the gas transportation corridor through Romania, Ukraine and Moldova.
Plans for a “Turkish Stream” to transport 63bcm of Russian gas through Turkey and on to Europe – bypassing Ukraine – have stalled since they were announced by the Russian and Turkish presidents in December 2014.
Turkey has to import nearly all the energy it consumes.
In 2012, Moscow and Ankara agreed to build Turkey’s first nuclear power plant, the Akkuyu plant. It was designed to save Turkey about $14bn (£9bn) annually on energy imports.
The nuclear power plant is now under construction in the province of Mersin on the Mediterranean coast. Russia has already invested $3bn in it.
In October, the Turkish authorities said Russia’s military activity in Syria could threaten its future involvement in the project.
President Recep Tayyip Erdogan said in October: “If the Russians don’t build Akkuyu, someone else will come along and build it.”
Construction and clothes
There are about 100 Turkish construction companies working in Russia.
Turkish firms have built more than 800 projects in Russia since the end of the 1980s, according to official Russian data.
Turkish investors also have stakes in a number of brands sold in the Russian market, such as Tevolina shoes and the Gloria Jeans clothes brand, as well as the food and chemical industries.
On Wednesday the Russian state-owned news agency RIA Novosti quoted Gennadiy Onishchenko, an aide to the Russian prime minister, as saying that people who bought Turkish goods financially supported Turkish servicemen.
“Everyone understands that each Turkish tomato bought… is a contribution to yet another missile which will be shooting at our guys,” he was quoted as saying.