A legal challenge against a controversial new land seizure law at the centre of a row with US President Donald Trump has been filed by the Democratic Alliance (DA), which is part of South Africa's coalition government.

U.S. President Donald Trump has followed through on his promise to punish South Africa by signing an executive order stopping all aid and assistance to the country over what he called a human rights violation against a white minority group.

South African President Cyril Ramaphosa said on Thursday that his country "will not be bullied," days after U.S. President Donald Trump said he would cut off funding to South Africa over a land reform act.