Ren Zhengfei, the billionaire founder of Huawei Technologies Co., broke a years-long silence to dismiss U.S. accusations the telecoms giant helps Beijing spy on Western governments.

Ren denied suggestions that Huawei aids the Chinese government in espionage, saying it has no regular contact with Beijing as his technology empire faces its biggest crisis in its three decades of existence. He also called Donald Trump “a great president” and said he’ll take a wait-and-see approach as to whether the U.S. leader...