NATO chief Jens Stoltenberg has said the military alliance will investigate French accusations that Turkey's navy failed to respond to an allied call for inspection this month in the Mediterranean.
Florence Parly, France's armed forces minister, brought up the incident on Thursday during a meeting of NATO defence chiefs at a time when the two allies have traded barbs over the crisis in Libya, accusing each other of supporting opposing sides in the country's war.
Paris has repeatedly accused Ankara of violating a United Nations arms embargo. Turkey rejects the French accusations and has denied that the incident as described by France ever occurred.
Parly said that on June 10 Turkish warships flashed their radar lights three times at the French warship Courbet in the eastern Mediterranean. She said the Courbet was on a NATO mission to check whether a Turkish vessel, the Cirkin, was smuggling arms to Libya after it turned off its transponder, failed to identify itself and did not give its final destination.
She added that Turkish sailors had also put on bullet-proof vests and stood behind their light weapons during the incident.
"There cannot be any complacency with regard to such behaviour. This particularly serious incident must be dealt with and our allies share our concerns because eight European allies gave me clear support today in NATO," Parly told French lawmakers after the ministerial meeting.
Turkish military officials on Thursday rejected the French accusations as baseless, according to state-run Anadolu news agency.
"The Turkish armed forces has the experience to tell the difference between hazardous moves, harassment, friendly activities, cooperation, solidarity, and coordination," a senior Turkish official, who asked not to be named due to restrictions on speaking to the media, was quoted as saying.
The official said France's claim was not backed up by any concrete evidence, and said the French ship was making fast and dangerous manoeuvres that breached NATO principles and navy security rules.
Turkey informed NATO civilian and military officials about the incident, he added.
Stoltenberg told a news conference on Thursday that the incident was addressed at the meeting by several alliance states.
"My message is that we have made sure that NATO military authorities are investigating the incident to bring full clarity into what happened," the NATO secretary-general told reporters.