Mr Farage accused Mr Van Rompuy of having the "charisma of a damp rag" and the appearance of "a low grade bank clerk" during the European President's maiden speech in his new role.
He also called Belgium a "non-country".
The EP President spoke with the Euro sceptic Euro MP on Tuesday asking him to apologise to Mr Van Rompuy, the people of Belgium and his colleagues in Parliament.
After Mr Farage failed to agree to do so, Mr Buzek withdrew the Euro MP's allowance for ten days.
Mr Farage told newsmen: "I thought long and hard about apologising and I'm going to apologise... to bank clerks across the world."