The South African government has given Taiwan a deadline of the end of March to relocate the island's de facto embassy outside of the capital city Pretoria, the Taiwanese Foreign Ministry said, blaming Chinese pressure for the move.

South Africa severed official diplomatic ties with Taiwan in 1997 and only maintains formal - and very close - relations with China, which views the democratically governed island as Chinese territory with no right to the trappings of a state.

In a statement late on Sunday, Taiwan's Foreign Ministry said South Africa's government had sent a letter in late January demanding the de facto Taiwanese embassy leave Pretoria before the end of March and "even be renamed as a trade office".

The demand "shows China's suppression against us in South Africa is becoming more serious", it added, saying, however, that negotiations between Taiwan and South Africa were ongoing.

China's foreign ministry said South Africa was a "good friend and partner" of China, and the country was doing exactly what it should when it comes to upholding the "one China principle" - which states Taiwan is part of China.

"Taiwan independence does not enjoy popular support, and will fail," the ministry said in a statement to Reuters.

The de facto South African embassy in Taipei did not respond to a request for comment.

South Africa had previously made a request last year for what is called the Taipei Liaison Office to leave Pretoria.

China is South Africa's largest trading partner globally and one with which it is looking to expand cooperation in areas such as renewable energy.

Taiwan's government rejects China's sovereignty claims and says it has a right to forge ties with other countries.

Taiwan only has formal diplomatic ties with 12 countries, and in Africa it only has a single ally left, Eswatini, which is almost entirely surrounded by South Africa.