Sykes, who joined the technology and comms company in early 2012, left at the start of July, Huawei confirmed today.
In a statement, the company said: "We regret to announce that Scott Sykes left the company in early July, due to personal reasons. During his tenure, Scott successfully led his team to strengthen the company’s relationships and communication efforts with international media and other stakeholders. We are extremely appreciative of his contributions to the company and wish him all the best in his future endeavours."
During his tenure at Huawei, Sykes led the company’s international media affairs team from its base in Shenzen, China.
While there, he helped shift international media perceptions of Huawei, whose equipment, some US critics argue, is potentially vulnerable to use by the Chinese government for the purposes of spying.
Previously, Sykes worked for Alcatel-Lucent as well as Weber Shandwick in Beijing and spent almost a decade working across Asia.
It is not yet clear what role Sykes will take up on his return to the US.