Britain said on Thursday it would cede sovereignty of the Chagos Islands to Mauritius in a deal it said secured the future of the U.K.-U.S. Diego Garcia military base, and which could also pave the way for people displaced decades ago to return home.

U.S. President Joe Biden welcomed the deal, saying it would secure the effective operation of Diego Garcia, a strategically important air base in the Indian Ocean, into the next century.

But critics in Britain said it was a capitulation that played into the hands of China, which has close trade ties with Mauritius.