Nato defences shot down an Iranian missile that entered Turkish airspace on Monday.
It is the second time a missile launched from Iran has been intercepted over alliance territory since the war started on Feb 28.
Officials said Nato equipment shot down the ballistic missile “heading towards Turkey”, with ammunition fragments landing in empty fields near Gaziantep in the south-central part of the country.
A Nato spokesman said the alliance “stands ready” to defend all members.
The incident prompted Mark Rutte, the Nato Secretary-General, to reiterate that Article 5 was not being invoked, amid concerns that member states could be drawn into the war.
In response, Turkey announced it would deploy six F-16 fighter jets to northern Cyprus to bolster regional defences.
Meanwhile, Sir Keir Starmer said on Monday that he was working to de-escalate tensions in the Middle East. Overnight, Pete Hegseth, the US defence secretary, said “this is only just the beginning”.