(CNN) Six retired US military leaders have issued a statement calling on America's allies to ban Chinese technology giants from outfitting their 5G networks, citing "grave concerns" over security.

The statement, released Wednesday, was signed by six highly-respected, retired US military officials, including former Director of National Intelligence James Clapper and former NATO Supreme Allied Commander in Europe James Stavridis.

"As military leaders who have commanded US and allied troops around the world, we have grave concerns about a future where a Chinese-developed 5G network is widely adopted among our allies and partners," the statement began.

The joint statement comes as New Zealand Prime Minister Jacinda Ardern refuted suggestions that Chinese technology company Huawei had been banned in her country

Huawei is one of China's largest technology companies and in recent years has become one of the most widely-used providers of super-fast 5G network technology globally.