BERLIN 

The shooting down of a Russian warplane on the Turkey-Syria border caused waves of concern Tuesday.

Pentagon: Russian pilot did not respond Turkish warnings

 The pilots of a downed Russian aircraft did not respond to Turkish military warnings, a spokesman for the U.S.-led anti-Daesh coalition said Tuesday.

Col. Steve Warren said coalition headquarters heard the incident on radar and confirmed Turkey’s military claim regarding the lack of response from the Russian pilots. The pilots were warned 10 times in 5 minutes, according to the Turkish Armed Forces. 

Warren described the downing of the aircraft as "an incident between the Russian and the Turkish governments” and not one involving the coalition.

International norms prohibits an alien aircraft from flying over another state's airspace, he said. 

"International norms are clear and well known by all players so there is no reason for an aircraft to fly over an area it shouldn't," Warren said. 

Two Turkish F-16s on patrol along the Syrian border engaged two Russian SU-24s before shooting one down after the warnings. 

The Russian defense ministry has announced an investigation into the crash.

Russian authorities said their planes were after Daesh in the area when it crossed the border.

Warren, however, said there are no Daesh targets in that area, expressing concern about Russian activities in Syria that go beyond targeting Daesh. 

Russian aircraft have accompanied forces of Syrian President Bashar al-Assad that are conducting offensives against opposition groups. 

Russian jets twice violated Turkish airspace last month. 

The U.S. last month deployed six F-15C air-to-air fighter jets to the Incirlik Air Base in southern Turkey to help Turkish jets patrol its borders. 

Warren told reporters that none of those U.S. aircraft were involved in the incident and there were no American aircraft or equipment in the vicinity where the incident happened. 

He noted, however, the F-15s that are protecting Turkish airspace are not part of the coalition and not operating within the parameters of an agreement singed last month with Russia about air safety above Syria. 

Warren declined to get into the rules of engagement of those aircraft.

'Keep channels open'

German Foreign Minister Frank Walter Steinmeier called on Russia and Turkey to keep channels open and avoid further tension.

“Now many things will depend on what the next reactions in Moscow and Ankara will look like,” he told reporters at a foreign ministers conference in Berlin. “First of all, I hope that both capitals will engage in direct talks. Secondly, I hope that authorities in Ankara and Moscow will be aware of their responsibilities, in terms of possible reactions and counter-reactions.”

Steinmeier called for “prudence and wisdom” to prevail so a political solution to the Syrian civil war was not jeopardized.

EU calls all sides to stay 'calm'

European Council President Donald Tusk said the incident was a “dangerous moment” in a post on Twitter and called for all sides to “remain cool-headed and calm”.

Federica Mogherini, the EU foreign policy chief, also tweeted that she had spoken to NATO Secretary General Jens Stoltenberg and said “avoiding escalation” was necessary.

UK 'ready' to call UN meeting on downing of Russian jet

The U.K. is prepared to call a UN Security Council meeting regarding the downing of a Russian jet after it violated Turkish airspace, Britain's UN envoy said Tuesday.

"As president of the Security Council, we stand ready to call a meeting on this issue, but so far no country expressed that wish," Matthew Rycroft told reporters following a council meeting on Sudan.

The incident demands all parties to redouble efforts to find a solution to the Syrian conflict, now in its fifth year, said Rycroft.

"In the meantime, we need to make sure that there are proper de-confliction measures in place to prevent accidents and incidents like this from happening again," he added.

A Russian SU-24 warplane was shot down while in Turkish airspace earlier Tuesday after repeatedly ignoring warnings that it was breaching the territory.

Russian jets previously violated Turkish airspace twice in October. The incidents occurred within a few days of the start of Russia’s air campaign in Syria on Sept. 30 and led to international condemnation.

Britain described the incident, in which Turkish F-16s brought down a Russian fighter-bomber after it crossed into Turkish airspace, as a “very serious incident”.

A Foreign Office spokeswoman said: “We are seeking further details urgently. Clearly this is a very serious incident but it would be unwise to comment further until we have more certainty on the facts.”

Addressing a news conference at the UN in Geneva, spokesman Ahmad Fawzi said the episode “might complicate” the regional situation.

Turkey informs UN over downed Russian warplane

Turkey has submitted a letter to the UN Security Council explaining the downing of a Russian jet early Tuesday after it violated Turkish airspace.

The letter, which was also sent to UN Secretary-General Ban Ki-moon and obtained by Anadolu Agency, said two SU-24 warplanes approached Turkish airspace in the Yayladagi region before Turkish authorities warned the planes via "emergency" channel and asked them to immediately change their headings.

Ten warnings were used during a 5-minute period.

"Disregarding these warnings, both planes, at an altitude of 19,000 feet, violated Turkish national airspace to a depth of 1.36 miles and 1.15 miles in length for 17 seconds," read the letter, adding that one of the planes left Turkish airspace after the violation.

The other plane "was fired at while in Turkish national airspace by Turkish F-16s performing air combat patrolling in that area in accordance with the rules of engagement " and "crashed onto the Syrian side of the Turkish-Syrian border”.

"Our rules of engagement are well known and reiterated to all parties on numerous occasions. Turkey will not hesitate to exercise its rights emanating from international law to protect the security of its citizens and borders in compliance with the established rules and regulations," it added.

Russian warplanes previously violated Turkish airspace twice in October. The incidents occurred within a few days of the start of Russia’s air campaign in Syria on Sept. 30 and led to international condemnation.

Meanwhile, Britain's UN ambassador expressed concern about the incident and called for de-escalation.

"The United Kingdom defends Turkey’s right to protect its own airspace", Matthew Rycroft told reporters in New York.

He said no member state had yet called for an emergency meeting of the Security Council.

Britain holds the council's rotating presidency for November.