"It's a free donation that will lead to nothing else," Mkhize told reporters in Bloemfontein on Thursday.
"There are no conditions attached. If it has conditions attached it is not acceptable."
There had been assertions that those who made a contribution to the party benefited from business ventures connected to the ANC and the state.
Mkhize said donations, whether local or foreign, did not form part of a transaction. Mechanisms were in place to ensure proper accountability on private donations.
The recommendations with regard to financing and fundraising were adopted by delegates at the ruling party's 53rd national conference in Mangaung, said Mkhize.
The party was largely funded by contributions from outsiders and members. Mkhize said the ANC had discussed a possible increase in membership fees, but decided against this. The party also debated public funding.
"This area of public funding is a way of supporting our democracy and … [we must] ensure it's accompanied by accountability and transparency. The ANC, like any other entity, should participate in the economy through various business activities so it can support its resources," he said.
There have been reports of concerns regarding the ANC's funding and budgeting for major conferences and events.
In his last financial report to the conference, former treasurer general Mathews Phosa said the party needed to assess the amount of money spent on rallies and events. Mkhize said this was an issue the party would attend to.
"Big rallies tend to require lots of resources and planning and so there is a need to balance that with costs. So in political mobilisation costs come out and we can't avoid those," Mkhize said, and congratulated Phosa on his management of the party's finances over the past five years.
"He's done a brilliant job. He has managed the affairs of the ANC quite effectively," he added – Sapa