Brussels (AFP) - NATO head Jens Stoltenberg on Saturday warned Russia it must "fully respect" alliance airspace as key member Turkey blasted Moscow for "irresponsible behaviour" over a new violation.
"I call on Russia to act responsibly and to fully respect NATO airspace. Russia must take all necessary measures to ensure that such violations do not happen again," Stoltenberg said in a statement.
"Previous incidents have shown how dangerous such behaviour is," he said.
In November, Turkey shot down a Russian fighter jet on the Syrian border, sparking a war of words with Russia which insisted its plane had not violated Turkish airspace.
Russia launched a massive air campaign in September against rebels fighting to overthrow Syrian President Bashar al-Assad, a long-time Moscow ally who Turkey bitterly opposes.
As in the November crisis, Stoltenberg called for "calm and de-escalation," welcoming contacts between Ankara and Moscow.
At the same time, he made absolutely clear that NATO would stand by Turkey, the second largest military power in the alliance after the United States.
"NATO stands in solidarity with Turkey and supports the territorial integrity of our ally, Turkey."
He recalled that the 28-nation alliance had agreed in December to help bolster Turkey's defences with the deployment of AWACS early warning and surveillance aircraft but added the caveat that this decision predated the latest incident.
Anakara called in the Russian ambassador on Friday "to strongly protest and condemn" the latest alleged violation of its airspace.
"We stress once again that all the responsibility for any unwanted grave consequences as a result of any such irresponsible behaviour will belong entirely to the Russian Federation," the Turkish foreign ministry said.