The drills -- just days before Moscow marks one year since its invasion of Ukraine -- have been slammed as tantamount to endorsing the Kremlin's onslaught on its neighbour.

A Russian military frigate was docked in Cape Town's harbour earlier this week for what a Russian diplomat called "refuelling" on its way to Durban.

The exercises, dubbed "Mosi" meaning "smoke" in the local Tswana language, are scheduled to take place between February 17 and 27 off the port cities of Durban and Richards Bay.

They are the second in a series of routine drills that Pretoria hosts with foreign nations, including Russia.

However, the latest will coincide with the first anniversary of Russia's invasion of Ukraine on February 24.

More than 350 members of South Africa's armed forces will take part in the exercises "with an aim of sharing operational skills and knowledge" with Russia and China, the military said last month.

South Africa has refused to condemn the invasion of Ukraine which has largely isolated Moscow on the international stage, saying it wants to stay neutral and prefers dialogue to end the war.

But the continental powerhouse has come under attack for hosting the joint drills.

"The event is being held on the anniversary of the invasion of Ukraine, so it's clearly a propaganda event aimed at bolstering support for the invasion," said Tim Cohen, an editor at the Daily Maverick newspaper in South Africa.

Pretoria's "pretense of being in favour of a negotiated solution to the Ukraine crisis dissolves with this exercise," he added.

The largest opposition party, the Democratic Alliance (DA), has been highly critical of the exercises, saying they "make South Africa complicit in these war crimes".

"We are drawn into the propaganda show of Russia," DA lawmaker Kobus Marais told AFP.

White House spokeswoman Karine Jean-Pierre last month said "the United States has concerns about any country... exercising with Russia, while Russia wages a brutal war against Ukraine".

Russia's consulate spokesman in Cape Town told AFP earlier this week that "South Africa, as any other countries (can) conduct military exercises with friends worldwide".

A South African military source told AFP "the main exercise" will take place on Wednesday next week.