BRUSSELS (AP) — NATO Secretary-General Jens Stoltenberg said Thursday that the military alliance is mulling how to respond to security concerns raised by some member countries about Chinese tech giant Huawei.

Stoltenberg says some of NATO’s 29 allies are uneasy about the potential security challenges of working with Huawei as they consider investment in 5G communications infrastructure.

The United States is lobbying European and other allies to shun the biggest maker of network technology as their phone carriers invest billions in upgrading to next-generation mobile networks.

Huawei rejects accusations that it might facilitate Chinese spying or is controlled by the ruling Communist Party.

Stoltenberg said the issue is being “addressed in many NATO capitals. It is an issue which is partly a trade and economic issue but also has potential security implications.”

“NATO takes these concerns very seriously,” Stoltenberg said. He said the allies “will continue to consult, continue to assess, and look into whether NATO has a role to play.” He refused to speculate about what it might do.

Following Stoltenberg’s remarks, the company issued a statement saying “there is no evidence that Huawei poses any threat to cybersecurity,” and that it is “open for dialogue with anyone who has legitimate concern on cybersecurity.”