Nato has warned Russia over its continued air strikes on targets in Syria, in support of President Bashar al Assad's government.
A statement by the body's 28 members urged Russia to end attacks "on the Syrian opposition and civilians" and warned of "the extreme danger of such irresponsible behaviour".
Russia violated Nato-member Turkey's airspace, drawing condemnation by the body.
"The Turkish Armed Forces are clearly instructed," Turkish Prime Minister Ahmet Davutoglu told Turkish TV.
"Even if it is a flying bird, it will be intercepted."
Turkey has again summoned the Russian ambassador, afterthe second violation of its airspace in two days.
UN spokesperson Stephane Dujarric expressed concern at the dangers of having "a lot of different countries and different coalitions" carrying out campaigns in Syria, saying the situation was "fraught with danger".