South Africa's military is in a "critical state of decline" due to chronic underfunding, threatening the country's defence capacity and its ability to take part in peacekeeping missions, a parliament report has warned.

"The defence force is in a critical state of decline," said the strategic review carried out by a parliament committee and posted on the assembly's website.

As a result of funding constraints, the army "is no longer in a position to conduct major combat operations, nor fully roll out the forces needed to safeguard South Africa's borders within the required timeframes," it warned.

The South African army is also "finding it increasingly difficult to sustain the deployment of its soldiers in the various peace missions across the continent."

As one of Africa's military powerhouses, the country has deployed troops to peacekeeping operations in the Democratic Republic of Congo and in Sudan's Darfur.

It previously deployed troops in Burundi. Its navy has also recently begun patrolling the waters off neighbouring Mozambique to ward off pirates.

Giving a bleak account of the state of defence forces in Africa's wealthiest nation, the report said it could take up to 10 years to get the military back into shape.

"Left unchecked, and at present funding levels, this decline will severely compromise and further fragment South Africa's defence capability."

South Africa's air force, arguably one of the best equipped on the continent, "remains critically underfunded," said the report.

The country's navy is also under "severe pressure" while the defence forces' ammunition stocks have been "depleted over time in certain crucial areas."

The 97,000-strong defence force is also "experiencing an alarming loss" of skilled personnel such as engineers, aircrew and legal officers.

"Even with an immediate intervention, it could take at least five years to arrest the decline and another five years to develop a limited and sustainable defence capability," said the review.

Inadequate funding has meant servicing of equipment is postponed while most of the military budget goes towards "personnel related expenditures."

The review, the second in two years, is due to be tabled in parliament for discussion.