The Associated Press earlier reported, citing unnamed US and Turkish officials, that Donald Trump had decided to withdraw American troops from Syria after a phone conversation with Turkey's President Recep Tayyip Erdogan.

Turkish President Recep Tayyip Erdogan promised his US counterpart Donald Trump that he would deal a coup de grace to the remainder of Daesh* forces in Syria once US troops are out, NBC News reported, citing a senior White House official. The pledge was allegedly made during a phone call on 14 December.

"Erdogan said to the president, 'In fact, as your friend, I give you my word in this'", the source said, speaking on condition of anonymity.

Another US official reportedly confirmed his words to the media outlet.

According to multiple media reports, including AP, Hurriyet, and NBC News, the decision was made after Erdogan told Trump that Daesh was nearly crushed, and there was no need for US troops to stay.

The sources also claimed that Defence Secretary Jim Mattis resigned after failing to convince Trump to maintain a military presence in the Mideast country.

Having faced fierce criticism over the sudden pullout both in Washington and beyond, President Trump defended his decision, lashing out at biased media coverage:

If anybody but your favorite President, Donald J. Trump, announced that, after decimating ISIS in Syria, we were going to bring our troops back home (happy & healthy), that person would be the most popular hero in America. With me, hit hard instead by the Fake News Media. Crazy! — Donald J. Trump (@realDonaldTrump) 23 December 2018

POTUS also slammed the national security staff that resigned this week, namely special envoy fot the anti-Daesh coalition Brett McGurk, who followed in the footsteps of Defence Secretary Jim Mattis and announced his resignation on Saturday.

Brett McGurk, who I do not know, was appointed by President Obama in 2015. Was supposed to leave in February but he just resigned prior to leaving. Grandstander? The Fake News is making such a big deal about this nothing event! — Donald J. Trump (@realDonaldTrump) 23 December 2018

In a follow-up tweet, Trump seemingly addressed a portion of Mattis's resignation letter, in which the Pentagon chief detailed the need for a close relationship with US allies:

When President Obama ingloriously fired Jim Mattis, I gave him a second chance. Some thought I shouldn’t, I thought I should. Interesting relationship-but I also gave all of the resources that he never really had. Allies are very important-but not when they take advantage of U.S. — Donald J. Trump (@realDonaldTrump) 23 December 2018

President Trump earlier wrote that Daesh had been "largely defeated", and the troops had to be withdrawn so that other countries, including Turkey, could take care of "whatever remains".

I am in the White House, working hard. News reports concerning the Shutdown and Syria are mostly FAKE. We are negotiating with the Democrats on desperately needed Border Security (Gangs, Drugs, Human Trafficking & more) but it could be a long stay. On Syria, we were originally… — Donald J. Trump (@realDonaldTrump) 22 December 2018

….going to be there for three months, 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! — Donald J. Trump (@realDonaldTrump) 22 December 2018

The Turkish newspaper Hurriyet cited Erdogan as saying that Ankara was "able to eliminate all terrorists" if Washington provided logistical support.

"Our target is not to conduct our diplomatic ties in a healthy way. We have the Turkish army and the Free Syrian Army capable of eliminating all these terror organisations, such as the PKK, YPG, and the PYD, just like we eliminated 3,000 ISIL [Daesh] members in Jarablus".

Speaking on Friday, Erdogan said that he had decided to postpone the military operation in Syria following a conversation with Trump:

“We will be working on our operational plans to eliminate ISIL [Daesh] elements, which are said to remain intact in Syria, in line with our conversation with President [Donald] Trump. In other words, over the next months, we will adopt an operational style geared toward eliminating PKK-PYD elements and ISIL [Daesh] residues”, he said.

On 19 December, Trump announced a decision to pull out all 2,000 troops from Syria starting immediately after he declared victory over Daesh.

READ MORE: Erdogan Decides to Postpone Military Op in Syria After Talk With Trump

Since 2014, the US-led coalition has conducted operations against Daesh in Syria without either a UN mandate or Damascus's authorisation; the Syrian government has repeatedly denounced Washington's military presence in the Mideast country as illegal.

*Daesh, also known as IS/ISIS/Islamic State, is a terrorist organisation outlawed in Russia and many other countries.