He served under six heads of state of South Africa, viz Jan Smuts, Dr DF Malan, JG Strijdom, Hendrik Verwoerd, John Vorster, and PW Botha.
Fourie was an aide to South African Prime Minister Jan Smuts during World War II and attended some of his meetings with UK Prime Minister Winston Churchill.
Fourie was the Secretary of Foreign Affairs for the Republic of South Africa in the 1970s and early 1980s.
In 1982, he was appointed South African ambassador to the United States, and served from 4 June 1982 until 23 September 1985.
On 21 November 1984, Fourie met four American activists (Mary Frances Berry, Randall Robinson, Walter E. Fauntroy and Eleanor Holmes Norton), who began changing U.S. public opinion about the apartheid regime by refusing to leave the embassy until their demands were met.