Obama and Erdogan agreed on the need to reduce tensions after Turkish forces shot down a Russian fighter jet, claiming it had entered Turkish airspace.

In a phone call, the two leaders concurred on the need to prevent a repeat of the incident as both Moscow and a US-led international coalition continue separate airstrikes against the so-called "Islamic State" (IS) militant group in Syria.

"They were in accord on the importance of de-escalating tensions and making arrangements to prevent a repeat of such incidents," the Turkish presidency said in a statement following the telephone talks.

The Russian SU-24 attack plane was shot down earlier Tuesday by two Turkish F-16s after the Russian pilots were warned 10 times - without a response, Turkish officials said.

"Stab in the back"

Despite Russian President Vladimir Putin vowing "serious consequences" for Turkey, earlier in the day, Obama said he hoped "all parties can step back and make a determination as to how their interests are best served."

Obama's comments follow a similar call by German Foreign Minister Frank-Walter Steinmeier.

United Nations Secretary-General Ban Ki-moon also called for urgent measures to de-escalate tensions, demanding a "credible and thorough review" of the incident to prevent a repeat.

"He urges all those who are engaged in military activities in Syria, especially air campaigns, to maximize operational measures to avoid unintended consequences," Ban's spokesman Stephane Dujarric said.

The downing is the most serious incident involving Russian forces since they entered the Syrian conflict in support of President Bashar Al-Assad in late September.

Repeated violations

Publicly, the US military backed up Turkey's claim that Turkish pilots had warned the Russian jet.

Pentagon officials have previously condemned the actions and tactics of Russian pilots after Russian jets twice violated Turkish airspace last month.

But the Kremlin maintained that the jet was flying at least a kilometer away from Turkish airspace.

Late on Tuesday, a US official - speaking on condition on anonymity - told Reuters that Washington also believes the Russian jet was hit inside Syrian airspace, after a brief incursion into Turkish airspace.

The pilots of the downed Su-24 ejected, but one was killed by Syrian rebel fire from the ground as he parachuted to earth, military officials in Moscow said.

One of two helicopters sent to the crash site to search for survivors was also hit by rebel fire, killing one serviceman and forcing the chopper to make an emergency landing, they added.

Short-term impact

Despite the spike in tensions, there was no immediate request for an emergency UN Security Council meeting. But analysts disagree over whether Russia and Turkey will let the incident escalate. The two share economic and energy interests and have a common opposition to IS.

"Relations have been very strained between Russia and Turkey of late, so Moscow will be trying its utmost to contain the damage this might cause," Natasha Kuhrt, a lecturer in international peace and security at King's College London told the Associated Press.

Hours after the incident, Obama and French President François Hollande held a joint news conference at the White House, calling on Moscow to cooperate in the fight against IS, but insisting that Moscow ends its support for Syria's embattled president Bashar al-Assad.

Hollande is due to meet with Putin on Thursday in Russia. as part of his diplomatic effort to build support for an intensified campaign against IS, which has claimed responsibility for the Paris attacks.

mm/bw (AFP, AP, Reuters)