LONDON (Reuters) - French President Emmanuel Macron accused Turkey on Tuesday of working with Islamic State proxies and said Ankara’s ambiguity toward the group was detrimental to its NATO allies fighting in Syria and Iraq.

France's President Emmanuel Macron looks on during a meeting with U.S. President Donald Trump (not pictured), ahead of the NATO summit in Watford, in London, Britain, December 3, 2019. REUTERS/Kevin Lamarque

Relations between Macron and Turkey’s President Tayyip Erdogan have soured ahead of Wednesday’s NATO summit in London with the two leaders trading barbs over Ankara’s cross-border offensive in northeast Syria targeting Kurdish militias.

Speaking alongside U.S. President Donald Trump, Macron directly linked Turkey to Islamic State fighters, while dismissing Trump’s concerns that Paris was not bringing home French Islamic State fighters held by Kurdish groups in Syria.

“The common enemy today is the terrorist groups. I’m sorry to say, we don’t have the same definition of terrorism around the table,” Macron told reporters.

“When I look at Turkey they are fighting against those who fought with us shoulder to shoulder against ISIS (Islamic State) and sometimes they work with ISIS proxies.”

Turkey has threatened to block a plan to defend Baltic states and Poland against Russian attacks unless the alliance backs Ankara in recognizing the Kurdish YPG militia as a terrorist group.

The YPG’s fighters have long been U.S. and French allies on the ground against Islamic State in Syria. Turkey considers them an enemy because of links to Kurdish insurgents in southeastern Turkey.

“I think any ambiguity with Turkey vis-a-vis these groups is detrimental to everybody for the situation on the ground,” Macron said. “The number one (priority) is not to be ambiguous with these groups, which is why we started to discuss our relations with Turkey.”

In an at times awkward news conference with Trump, Macron appeared exasperated when the U.S. president said he would pass the question to Macron on whether France should do more to bring French ISIS fighters home.

Paris has about 400 nationals, including around 60 fighters, held in northern Syria. It has refused to bring adults home saying they must face trial where their crimes were committed.

“Would you like some nice ISIS fighters? You can take everyone you want,” Trump said in a light-hearted tone.

Visibly irritated, Macron responded, saying “let’s be serious” and argued that number of foreign fighters from European countries was small, and that it would be unhelpful to focus on them rather than on the broader problem.

“It is true you have fighters coming from Europe but this is a tiny minority and I think the number one priority, because it’s not finished, is to get rid of ISIS and terrorist groups. This is our number one priority and it’s not yet done,” he said.

Trump suggested Macron had not answered the question.

“This is why he is a great politician because that was one of the greatest non-answers I have ever heard, and that’s OK,” Trump said.