Russia is accusing Turkey of shooting down its fighter jet on the Syrian border in order to protect its oil trade with ISIS.
Speaking at international talks on climate change in Paris, Russian President Vladimir Putin called the warplane’s downing a “huge mistake”.
Turkey has denied any ties to ISIS and is part of a US-led coalition carrying out airstrikes against the militant group.
The Turkish government has refused to apologize for the incident.
One Russian pilot was killed and the other rescued following the crash on November 24. Turkey says the plane entered its air space – an accusation Russia denies.
On November 30, the US state department said evidence from Turkish and US sources indicated the aircraft did violate Turkish airspace.
Spokeswoman Elizabeth Trudeau said the US wanted to “encourage dialogue now… we need to de-escalate the situation”.
Russia has been carrying out air strikes in Syria, targeting rebels against Syrian President Bashar al-Assad, including ISIS.
Turkey is a vehement opponent of Bashar al-Assad and has been accused of turning a blind eye to jihadist fighters crossing from its territory into Syria.
Until a few months ago, Turkey was reluctant to play an active role in the coalition against ISIS. However, in August it allowed the US-led coalition to begin using its airbase at Incirlik.
Russia has imposed sanctions on Turkey over the downing of the plane, including restrictions on imports of Turkish food and an end to visa-free travel.
ISIS earns much of its money from illegal sales of oil – however, Turkey has staunchly denied that it is involved in the trade.
“We have every reason to think that the decision to shoot down our plane was dictated by the desire to protect the oil supply lines to Turkish territory,” Vladimir Putin said at a news conference in Paris on November 30.
The Russian president said his president had received more information to show that ISIS oil was passing through Turkish territory.
Earlier Turkish PM Ahmet Davutoglu said the incident was unfortunate but that Turkey had a right and duty to protect its airspace and would not apologize.
On November 30, Russia said it would ban mainly imports of agricultural products, vegetables and fruits from Turkey, although it may delay the restrictions for several weeks to “ease inflationary pressure”.
Turkish industrial goods would not be banned for now but future expansion of the sanctions was not ruled out, officials said.
Turkey and Russia have important economic links. Russia is Turkey’s second-largest trading partner, while more than three million Russian tourists visited Turkey in 2014.
Turkish President Recep Tayyip Erdogan said Turkey will act “patiently, not emotionally” before deciding its response to the economic sanctions.