The chief of China's football association has told the country's players not to lose their confidence, after the team's embarrassing loss to war-torn Syria jeopardised hopes of qualifying for the 2018 World Cup.

The national side's 0-1 defeat Thursday before a home crowd of 40,000 in the northern Chinese city of Xi'an had enraged fans, spurring many to call for the sacking of China's football association president Cai Zhenhua.

But he has ignored the calls so far, and sought to reassure Team Dragon players they "absolutely must not lose confidence because of this loss," the Xin Kuaibao newspaper reported Saturday.

"We still have seven games, you must bring out your fighting spirit. Especially at times like this (after a loss), you mustn't give up."

The association told AFP it would not be making further comment on the defeat.

China's national team wrote a message after the Syria loss on their official Weibo social media account thanking fans for their "unending cheers" and "fighting by our side".

"You are our pride, and to all our fans who came out yesterday, we'd sincerely like to say we're grateful we have you, thanks for all your trouble," it said on its official account Friday.

"With you there, we can face every defeat, and we can overcome every setback. Keep your head up, we'll continue the struggle!"

China's beleaguered fans have a well-developed sense of humour about the travails of their national side, who are ranked a lowly 78th in the world and have failed to qualify for the World Cup since their first and only appearance in 2002.