China on Monday hit back a U.S. report that claimed there is evidence that some of China's state-owned firms may be helping Russia in Ukraine, stressing Washington itself is the culprit and the leading instigator of the Ukraine crisis.

At a regular press briefing, Chinese Foreign Ministry spokesperson Mao Ning pointed out the U.S. is continuously sending heavy weapons and offensive weapons to Ukraine and constantly increasing the length and intensity of the conflicts.

"Rather than reflecting on its own acts, the U.S. side is making unfounded suspicions and accusations against China," Mao stressed, adding the Chinese side reject such groundless blackmail and would not sit by and watch the U.S. harm the legitimate rights and interests of Chinese enterprises.

The spokesperson reiterated China has all along held an objective and just position on the Ukraine issue, always stood on the side of peace and played a constructive role in promoting a political solution to the Ukrainian crisis.

China did not stand idly by or add fuel to the fire, still less exploit the crisis, Mao noted.

She said the U.S. should stop sending weapons if it wants the conflict to end while urging the U.S. side to promote the situation to cool down as soon as possible in a responsible manner, and create favorable and necessary environment and conditions for peace talks between Russia and Ukraine.