Following US President Donald Trump's decision to withdraw military forces from Syria, US Secretary of Defense Jim Mattis announced that he would leave the office at the end of February.

Mattis announced his decision with a letter of resignation. In his letter of resignation, Mattis said, "Because you have the right to have a secretary of defense whose views are better aligned with yours on these and other subjects, I believe it is right for me to step down from my position." Mattis pointed out 28 February as his deadline in his letter.

Jim Mattis's decision to leave office was followed by President Trump's decision to withdraw military forces from Syria and the news in the US media that the Trump administration is preparing to reduce the number of troops in Afghanistan.

Trump thanked Mattis for his service on Thursday and praised him for making a contribution to his administration.

"General Jim Mattis will be retiring, with distinction, at the end of February, after having served my administration as secretary of defense for the past two years," Trump said on Twitter.

"A new Secretary of Defense will be named shortly. I greatly thank Jim for his service!" he added.

The US media reported that Jim Mattis went to the White House to make Trump change his decision not to withdraw from Syria, but submitted his resignation letter when Trump did not change his mind.

ILKHA