Finance Minister Tito Mboweni said Treasury has provided SAA with financial support to the best of its abilities.
Mboweni addressed business leaders in Johannesburg on Thursday morning ahead of the World Economic Forum annual meeting in Davos next week.
SAA entered a form of bankruptcy protection last month in an effort to rescue the company and 10,000-related jobs.
The National Transport Union said it was concerned with the slow pace government was taking to provide R2 billion it promised.
At the time, it was promised R2 billion from the government and R2 billion from lenders.
The union has warned that without the money, there could be dire consequences such as suspended flights and delay in salary payments.
The union’s Mashudu Raphetha said: “One of the lenders is saying government must show them what size it’s going to be at SAA before they give us the loan.”