The office of South African President Jacob Zuma is countering opposition accusations that he is wasting millions of dollars on chartered jets at a time when the country's economy is struggling.

The statement Wednesday says Zuma has had to use chartered aircraft because there are no reliable planes in the air force for official trips.

The president's office says it agrees that the use of the air force fleet for trips by Zuma and Deputy President Cyril Ramaphosa would reduce costs.

South Africa's ruling party has lost support partly because of voter dissatisfaction over corruption allegations against Zuma.

The president announced this week that he has paid the state more than $500,000 after being instructed to do so in a scandal over state-funded upgrades to his private home.