WASHINGTON - US President Donald Trump took to Twitter earlier this week to announce that Defence Secretary James Mattis would resign on 28 February 2019.

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Pentagon chief Jim Mattis’ departure from the White House was spurred by a phone conversation between Donald Trump and his Turkish counterpart Recep Tayyip Erdogan, in which POTUS decided to withdraw troops from Syria, The Associated Press reported, citing two US officials and a Turkish official briefed on the matter.

According to the insiders, the call took place on 14 December – just a day after Secretary of State Mike Pompeo and Turkish Foreign Minister Mevlut Cavusoglu agreed to have the two presidents discuss Erdogan’s threats to kick off a military operation against US-backed Kurdish militia in Syria.

The sources claim that Trump, who previously convinced his Turkish counterpart not to put US troops at risk, made a U-turn, thus siding with Erdogan, while Pompeo, Mattis and other national security officials tried to talk him out of it.

“The talking points were very firm. Everybody said push back and try to offer [Turkey] something that’s a small win, possibly holding territory on the border, something like that”, one of the sources told AP.

Erdogan allegedly reminded Trump that he had on multiple occasions said that the only reason for US troops to maintain a presence in Syria was to crush Daesh*, and that the terrorist group had been 99 percent defeated.

According to the sources, POTUS immediately asked his national security adviser John Bolton to clarify why American forces remained in Syria if Erdogan’s words were true.

Bolton purportedly said that the Turkish president’s point had been backed up by Mattis, Pompeo, US special envoy for Syria Jim Jeffrey and special envoy for the anti-Daesh coalition Brett McGurk, who claimed that terrorists retained only one percent of their territory.

At the same time, the insiders alleged, that Bolton noted that the national security team agreed that a win over Daesh had to be “enduring”.

Trump, according to the officials, pledged to withdraw, leaving both Bolton and Erdogan in a state of shock. Although Erdogan cautioned him against a hasty pullout, Trump reiterated that he would deliver on his promise as their conversation came to an end. A similar account is reported by the Turkish newspaper Hurriyet.

While Turkish officials are yet to comment on the claims, the US National Security Council rejected the description of the call.

 “In no uncertain terms, reporting throughout this story is not true. It is clear from the context that this false version of events is from sources who lack authority on the subject, possibly unnamed sources in Turkey”, National Security Council spokesman Garrett Marquis was cited by AP as saying.

Mattis and other high-ranking officials reportedly sought to change Trump’s mind over the weekend, but did not succeed. On 20 December, he handed over his resignation letter to POTUS, suggesting that Trump had the right to have a defence secretary “whose views are better aligned with yours on these and other subjects”, without specifying the exact reason for his abrupt decision.

Mattis’s resignation followed Trump’s Wednesday decision to pull out all 2,000 troops from Syria starting immediately after he declared victory over Daesh.