Emmanuel Macron
Emmanuel MacronReuters

French President Emmanuel Macron on Sunday criticized US President Donald Trump's decision to withdraw American forces from Syria, saying "an ally must be reliable", AFP reported.

"I deeply regret the decision" by Trump to pullout US troops, he added, according to the report.

"An ally must be reliable, to coordinate with its other allies," Macron continued, hinting at his own disappointment at the frayed relations with the US.

Trump last week ordered a complete troop pullout from Syria, asserting that the Islamic State (ISIS) group had been defeated, as well as a significant withdrawal from Afghanistan.

Trump on Friday defended his decision to withdraw troops from Syria which, tweeting, “I’ve done more damage to ISIS than all recent presidents....not even close!”

On Saturday, Trump issued another tweet explaining his Syrian withdrawal strategy.

"On Syria, we were originally going to be there for three months," Trump wrote. "And that was seven years ago - we never left.”

"When I became President, ISIS was going wild. Now ISIS is largely defeated and other local countries, including Turkey, should be able to easily take care of whatever remains. We’re coming home!" he added.

France has said it will maintain its participation in the coalition fighting ISIS in Syria.

"To be an ally is to fight shoulder to shoulder," Macron said in Chad's capital N'Djamena with his Chadian counterpart Idriss Deby, adding that France was doing just that in the fight against jihadist groups in central African country.

In his remarks, Macron also paid tribute to Defense Secretary James Mattis, who announced he was resigning on Thursday, in part due to the Syria decision.

"I want here to pay tribute to General Mattis... for a year we have seen how he was a reliable partner," Macron said, according to AFP.