Huawei is reportedly bemused by two US senators getting hot under the collar about the Chinese firm’s recent LTE contract win with LG Uplus, a South Korean mobile operator.

US Senator Dianne Feinstein, chairman of the Select Committee on Intelligence, and Senator Robert Menendez, who leads the Committee on Foreign Relations, sent a letter last week to Defence Secretary Chuck Hagel, Secretary of State John Kerry and James Clapper, the director of national intelligence.

They are concerned, according to a Bloomberg report, that the Chinese firm’s involvement created risks for the US-South Korea alliance, including US troops based on the peninsula.

“Our gear is world-proven and trusted, connecting almost one-third of the world’s population,” Scott Sykes, a spokesman for Huawei, said in an e-mail, quoted by Bloomberg. “The motivations of those that might groundlessly purport otherwise are puzzling.”

In quotes carried by the Financial Times, Sykes is more outspoken. He complained of “trade protectionism, Sinophobia and discrimination based on where our headquarters are”.

“Huawei is not China; Huawei is Huawei,” he added. Leading US companies such as Apple carried out much of their production in China, so why don’t the same standards not apply to those companies? he asked.

Kim Sang Yup, a spokesman for LG Uplus, said in a phone interview with Bloomberg that the mobile operator hadn’t considered ending its contract with Huawei because of US concerns.

“All we get from Huawei is their network equipment,” Kim said. “Other network-related maintenance and operations will be handled solely by us and through our domestic partners, so Huawei will have no access to our network operations as soon as the equipment is handed over.”

Huawei has had to contend with security suspicions from various western national governments.

Deputy chairman, Ken Hu, in a foreword to the Chinese supplier’s recent white paper on cyber security, said any notion that the firm might be involved in government-backed cyber hacking is entirely unfounded.

Huawei’s chief executive officer, Ren Zhengfei, reportedly said in a recent interview with Les Echos that the company will stop looking for new business in the US, saying “it’s not worth it” if the company gets entangled in US-China relations.