File Photo: Syrian schoolchildren walk as U.S. troops patrol near Turkish border in Hasakah, Syria Nov. 4, 2018. (Xinhua/REUTERS)

UNITED NATIONS, Dec. 20 (Xinhua) -- Outgoing UN Special Envoy for Syria Staffan de Mistura on Thursday was unwilling to comment on U.S. President Donald Trump's decision to withdraw troops from Syria.

"It is totally premature for making any comment on my side on the implications, the effects of that important decision, which was announced yesterday -- both on the political ground and on the military ground," de Mistura told reporters after his briefing to the Security Council.

"I am unable to make any comment. It's premature for me to do so."

De Mistura, after more than four years as UN special envoy for Syria, steps down by the end of the year. He will be replaced by Geir Pedersen of Norway.

The White House said Wednesday that the Trump administration has started returning U.S. troops home from Syria after claiming victory in the fight against the Islamic State terrorist group in the region.

Asked earlier Thursday to comment on the U.S. decision, French ambassador to the United Nations Francois Delattre said: "We need more than ever America's political commitment to a political solution in Syria."