NATO confirmed on Monday that it had intercepted another missile heading to Turkey.
"NATO stands firm in its readiness to defend all allies against any threat," NATO spokesperson Allison Hart said in a post on X.
Turkey said earlier on Monday that NATO air defenses shot down a second ballistic missile that was fired from Iran and had entered Turkish airspace, warning that it will take any necessary steps against threats.
This marks the second Iranian ballistic missile in the last week that has targeted the south of Turkey, which is a NATO member and Iran's neighbour. Ankara had warned Iran against attacking again on Saturday, but has not suggested it wants to formally call on alliance members for further protection.
"We once again emphasize that all necessary measures will be taken decisively and without hesitation against any threat directed at our country's territory and airspace," the Turkish Defence Ministry said, adding some ammunition parts had fallen in the southeastern province of Gaziantep but there had been no casualties.
"We also reiterate that it is in everyone's interest to heed Turkey's warnings in this regard," it said.
It was unclear where the missile was headed before it was intercepted by NATO defenses stationed in the eastern Mediterranean Sea.
US air forces are stationed at the Incirlik base in southern Turkey, and there is a NATO radar base in Malatya province to the northeast that provides vital protection for the alliance. Ankara said fragments from the missile fell in empty fields in Gaziantep, which sits roughly between the two.
Turkey warns all sides, especially Iran, to avoid escalation
Burhanettin Duran, President Tayyip Erdogan's communications director, said Ankara was strongly reiterating its warning to all parties, namely Iran, to avoid steps that endanger regional stability and civilians.
Ankara says that Washington has not used Incirlik in its air assault, alongside Israel, on Iran, which triggered Tehran's missile and drone attacks.
Iran did not immediately comment on the incident, but it has said repeatedly that it is not at war with regional countries and is not explicitly targeting Turkey.
Turkey, which had sought to mediate US-Iran talks before the air war that began last week, has previously said it had no intention currently of invoking NATO's Article 4that would call allies to consult if a member is threatened.
That could lead to invoking the alliance's Article 5, which would call NATO to defend its attacked ally.
Turkey has the trans-Atlantic alliances' second-largest army and has become a leading global actor in the defense industry in recent years. However, it still lacks fulsome air defense of its own despite efforts to develop them. It has relied on NATO's air defenses in both incidents in the last week.