Russia says Turkey 'shot down plane for IS oil'
Russia has accused Turkey of shooting down its warplane near the border with Syria in order to protect its oil trade with the Islamic State (IS) group.
Speaking at international talks on climate change in Paris, Russian President Vladimir Putin called the downing of the plane a "huge mistake".
Turkey has denied any ties to IS and is part of a US-led coalition carrying out air strikes against the militant group.
The Turkish government has refused to apologise for the incident.
One Russian pilot was killed and the other rescued following the crash on 24 November. Turkey says the jet entered its air space - an accusation Russia denies.
On Monday 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".
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Russia has been carrying out air strikes in Syria, targeting rebels against Syrian President Bashar al-Assad, including IS.
Turkey is a vehement opponent of Mr 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 IS. 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.
IS 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," Mr Putin said at a news conference in Paris on Monday.
He said Russia had received more information to show that IS oil was passing through Turkish territory.
Earlier Turkish Prime Minster Ahmet Davutoglu said the incident was unfortunate but that Turkey had a right and duty to protect its airspace and would not apologise.
Russia said on Monday 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 last year.
Turkish President Recep Tayyip Erdogan said his country will act "patiently, not emotionally" before deciding its response to the economic sanctions.