The Democratic Alliance (DA) has taken exception to Defence Minister Lindiwe Sisulu's decision to classify details of President Jacob Zuma's flights.

In written reply to a Parliamentary question on Monday, Sisulu said that Zuma undertook 27 international and 133 domestic flights from May 9 last year to date.

The DA's David Maynier had asked Sisulu for details of each flight, including the dates, departure and arrival points, and the costs involved.

Sisulu declined to answer, saying that the "information required is classified and may not be made public".

However, Maynier was advised to raise this request with the Joint Standing Committee on Defence and Military Veterans, she said.

In a statement later, Maynier said that this information had been made public in the past.

Sisulu's reply raised questions about why she was "now covering up details about flights" undertaken by Zuma.

"The fact is that the minister's refusal to provide full information on flights undertaken by President Jacob Zuma is part of a trend of defence department resistance to being properly accountable to Parliament.

"The real question is what is the minister trying to cover up. Is she trying to cover up details of the routing of the aircraft, the names of the passengers or the exorbitant costs of operating the aircraft?" Maynier asked.