"Providing support and convenience for the construction of diplomatic premises is an international obligation of the host country," Guo Jiakun told a news conference.

The 20,000-square-metre (235,000-square-foot) site is set to become the largest embassy complex in the UK by area, and one of the largest in the centre of a Western capital.

Plans for the embassy triggered anger and protests from rights groups and activists, who fear the site could be used to spy on and harass dissidents.

While British housing minister Steve Reed said the decision was final, it could still face legal challenges, with residents in London vowing to act.

Ties between China and Britain plummeted under the previous Conservative government, with the new embassy appearing to be a sticking point.

British Prime Minister Keir Starmer, whose Labour party swept to power in 2024 elections, has sought to reset ties with the economic powerhouse, and will reportedly visit China later this month.

While the embassy approval could boost relations, security minister Dan Jarvis noted that China would still continue to pose national security threats to Britain.