NATO apologised to Turkey on Friday after Ankara pulled its troops from a military exercise in Norway where President Recep Tayyip Erdogan and the country's modern founder Mustafa Kemal Ataturk had been portrayed as enemies of the alliance.

The alliance's Secretary General Jens Stoltenberg, himself Norwegian, moved quickly to say sorry after an angry intervention by Erdogan over an embarrassing episode that risked creating a further rift between Turkey and its allies.

The incidents took place during NATO's "Trident Javelin" exercise in the southern Norwegian city of Stavanger aimed at increasing coordination between the allies at headquarters level, which wound up Friday.

Erdogan said that Ankara had withdrawn its 40 troops from the exercise in protest, adding: "It's not possible to have this kind of alliance".

Norway's Defence Minister Frank Bakke-Jensen, speaking to AFP, also expressed "regret" over the incident.

- 'Pull them out now' -

Turkey's foreign ministry said that an image of a statue of Ataturk had been used to portray an enemy protagonist in a scenario at the exercise.

In a second incident, a chat account was opened under Erdogan's name during a virtual scenario as a collaborator with a "leader of an enemy state".

Erdogan said Turkey's top general Hulusi Akar and EU Affairs Minister Omer Celik -- who were on their way to a NATO conference in Halifax, Canada -- had informed him of the incident.

"They said 'this has happened... and we are going to take out our 40 soldiers'," Erdogan said while speaking in front of giant pictures of himself and Ataturk.

"And I said 'Absolutely, don't hesitate, take them out right now'."

Ataturk founded modern Turkey out of the ruins of the Ottoman Empire in 1923 and is widely credited with salvaging a functioning Turkish state in the 1919-1923 War of Independence.

Insulting his memory is a criminal offence in Turkey that is punishable by jail. It is also an offence to insult top state officials such as Erdogan.

Ankara prosecutors said in a statement they had opened a criminal investigation against an individual or individuals who had denigrated and insulted Ataturk and Erdogan in the incidents.

While critics accuse Erdogan of tainting the secular vision of Ataturk, the president has in recent months made increasingly clear his admiration for Turkey's modern founder.

On the November 10 anniversary of Ataturk's death in 1938, Erdogan eulogised Turkey's first president, saying he should be remembered with "grace and gratitude".

- 'Valued NATO ally' -

Turkey, which became a member of NATO in 1952, is a key member of the alliance but tensions have grown in recent months over its crackdown after a failed coup and Ankara's increasingly close alliance with Russia.

Its Western allies have been particularly troubled by a deal for Ankara to purchase an S-400 air defence system from Russia and the cooperation between Ankara, Moscow and Tehran on the Syria crisis.

Stoltenberg, a former Norwegian prime minister, in his apology emphasised the importance of Turkey within the alliance.

"I apologise for the offence that has been caused. The incidents were the result of an individual's actions and do not reflect the views of NATO," Stoltenberg said in a statement.

"Turkey is a valued NATO ally, which makes important contributions to allied security."

Stoltenberg later passed on the apology in person to Akar at a meeting in Halifax, the Turkish army said.

The Trident Javelin exercise in Stavanger is described on a NATO website as a "computer assisted exercise without troops on the ground", aimed at improving command structures for major operations.

Stoltenberg also said the individual responsible for the incident was not a NATO staff member.

"He was a civilian contractor seconded by Norway and not a NATO employee," Stoltenberg said.

"It will be for the Norwegian authorities to decide on any disciplinary action. NATO has been in contact with the Norwegian authorities on this issue."

Source: AFP