Opponents of a controversial South African land expropriation bill are calling the legislation a threat to private ownership after it was endorsed by the country's president.

South African President Cyril Ramaphosa has signed into law a bill allowing land seizures by the state without compensation - a move that has put him at odds with some members of his government.

Presidency announced in a statement on Thursday that President Cyril Ramaphosa had signed into law the Expropriation Bill, which repeals the pre-democratic Expropriation Act of 1975 and sets out how organs of State may expropriate land in the public interest for varied reasons.