Debris from a missing Canadian helicopter taking part in a NATO operation has been found in the Ionian Sea between Greece and Italy, a Greek military source said Thursday.

"Debris has been found in Italy's zone of control and intervention" in the Ionian Sea, the source told AFP. "Greece has sent a marine helicopter to participate in the rescue operation."

Washington and the Taliban are set to sign a landmark deal in Doha on Saturday that would see them agree to the withdrawal of thousands of US troops from Afghanistan in return for insurgent guarantees.

NATO's ruling council will meet Friday for urgent talks on the Syria crisis after at least 33 Turkish soldiers were killed in an air strike blamed on Damascus.

The US-led NATO mission in Afghanistan has stopped releasing key data on how much of the country falls under insurgent or government control, a US watchdog said Wednesday, the latest war metric to fall from public view.

NATO Secretary General Jens Stoltenberg was due to meet President Donald Trump Tuesday ahead of celebrations for the 70th anniversary of the alliance, a frequent target of the US leader.

Seventy years after it was formed to counter the Soviet Union, Russia has returned to the top of the agenda for NATO. But the alliance faces another, more unlikely problem -- criticism from the US president.

NATO does not want a new arms race with Russia, the alliance's secretary general said Wednesday amid heightened tensions following an ex-spy's poisoning in England.

NATO chief Jens Stoltenberg on Monday told allies to boost defense spending, as demanded by U.S. President Donald Trump, if they want to preserve crucial transatlantic defense ties.

NATO chief Jens Stoltenberg on Tuesday said the top priority for the transatlantic alliance is to increase defense spending, as demanded by U.S. President Donald Trump.

NATO has begun training Iraqi soldiers on how to neutralize bombs planted by the Islamic State jihadist group, the alliance said Sunday, expanding a program already in place in neighboring Jordan.