Obama tells Russia, Turkey to focus on IS

US President Barack Obama led called on Tuesday for Turkey and Russia to end their dispute over the downing of a Russian fighter jet and focus instead on the real enemy - Islamic State (IS) fighters.

It came as Obama's Pentagon chief said the US would increasingly rely on special operations forces to battle IS in Iraq and Syria, where the group has seized huge swathes of territory including oil fields used to fund their activities.

The US president said he was sure that Russia would soon change tack in Syria and back a political solution to the bloody conflict after years of supporting long-time ally President Bashar al-Assad, who Washington insists must step down.

And NATO chief Jens Stoltenberg urged Turkey and Russia to find a way to avoid a repeat of the jet incident, which threatens to scupper efforts to forge a common anti-IS front in the wake of attacks in Paris claimed by the group that left 130 dead.

Obama was frank about what both sides should do.

"I want to be very clear: Turkey is a NATO ally. The US supports Turkish rights to defend itself and its airspace and its territory," Obama said after meeting his Turkish counterpart Recep Tayyip Erdogan in Paris.

"We all have a common enemy and that is ISIL, and I want to make sure we focus on that threat," Obama said, using an alternative name for IS.

Erdogan, who has demanded that Russian President Vladimir Putin provide evidence to back up its charges that Ankara trades in oil with the IS group, said he too was keen to move on.

"We are always willing to resort to the diplomatic language ... we want to avoid the tensions," he said.

Calm tensions, avoid repeat

Stoltenberg, speaking at the start of a two-day meeting of NATO foreign ministers, said the focus should be on "how we can de-escalate and calm tensions (and find) mechanisms so that we can avoid the type of incident we saw last week."

The Turkish air force shot down the Russian jet last week for allegedly violating its airspace near the Syrian border.

One Russian pilot was shot dead in Syria after parachuting from the burning aircraft, while the second was found safe. One Russian soldier was killed in a rescue operation.

Obama, who took a conciliatory tone in a meeting on Monday with Putin, said on Tuesday that he believed Moscow would soon realise that the cost of its military intervention in support of Assad outweighed the benefits.

"Ultimately, Russia's going to recognise the threat that (IS) poses to the country, to its people, is the most significant and that they need to align themselves with us who are fighting ISIL," Obama said.

Pentagon chief Ashton Carter meanwhile announced that Washington would deploy a special expeditionary force to Iraq - and hinted more forces could be sent to Syria - after more than a year of US-led coalition air strikes on the group.

"The international community - including our allies and partners - has to step up before another attack like Paris," he said, with Britain's parliament to vote on Wednesday on joining the air raids on IS targets in Syria.

Russia, Turkey trade barbs

Putin said he believed the decision to shoot down the Russian fighter jet was meant to cover up Turkish involvement in the IS oil trade, sparking a furious response from Erdogan.

"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, right to the ports where it is loaded onto tankers," Putin said during a news conference on the fringes of UN climate talks near Paris.

"We have received additional information which unfortunately confirms that this oil, produced in areas controlled by IS and other terrorist organisations, is transported on an industrial scale to Turkey."

The Russian leader had earlier snubbed a request by Erdogan to meet on the sidelines of the conference.

"A claim is made through evidence. If there's such evidence, then put it on the table and we will look," Erdogan said, adding he would resign if the allegations were proved to be true.

Ankara has also ruled out making an apology demanded by Moscow.

Russia announced a series of retaliatory sanctions aimed at Turkey's key tourism and agricultural sectors.

Moscow has boosted its military presence in Syria, deploying top-range S400 missiles and new naval forces in support of Assad.

In a rare interview, Assad told Czech TV that peace would only come to Syria when the West and its Middle Eastern allies - naming the United States, Britain, France, Saudi Arabia and Qatar - "stop supporting terrorists".

All of those countries have demanded that Assad step down and have backed rebels fighting his troops.