NATO leaders said Monday they would join forces against the "systemic challenges" posed by China's policies, as US President Joe Biden renewed Washington's Transatlantic ties at his first summit with the allies.

In a broad statement of intent, the leaders said China's increasingly assertive actions in building a nuclear arsenal and space and cyber warfare capabilities threatened the international order.

In an angry response, a statement from the Chinese Mission to the European Union called for NATO to "view China's development rationally, stop exaggerating various forms of 'China threat theory' and not to use China's legitimate interests and legal rights as excuses for manipulating group politics (while) artificially creating confrontations".

It added that NATO's accusations were a "slander of China's peaceful development, a misjudgment of the international situation and its own role, and it is the continuation of a Cold War mentality and the group's political psychology at work".

NATO Secretary General Jens Stoltenberg said the allies would seek to cooperate with China on global issues like climate change -- but decried Beijing's increasingly assertive stance on other issues.

It came a day after the Chinese embassy in Britain hit back at the G7 for "political manipulation" after the group criticised China's human rights record in Xinjiang and Hong Kong.