Kenyan President Uhuru Kenyatta has been welcomed by President Cyril Ramaphosa to start a two-day state visit to South Africa.
Kenyatta's visit comes as a nearly yearlong war in the Tigray region of northern Ethiopia continues to roil the region.
Kenya, which shares a border with Ethiopia, has long had a strong relationship with the US, partnering with Washington in efforts to thwart Islamic terrorism.
A probe has been ordered of the country's election commission for alleged "irregularities and illegalities" in the conduct of August's annulled presidential poll.
The Supreme Court on September 1 declared Kenya's August 8 presidential election "invalid, null and void" after hearing a legal challenge filed by the opposition, led by Raila Odinga.
Accused of glossing over flaws in Kenya's election which later caused the result to be overturned, international observers are under a harsh spotlight ahead of a re-run next month.
Kenyan judges have slammed the "veiled threats" made by President Uhuru Kenyatta after the judiciary overturned his election on the ground that it was flawed.
Kenyatta says the country's judiciary has a "problem" and his administration will revisit the issue once it is reelected.
Praise poured in Saturday for Kenya's judiciary after a historic ruling annulling presidential poll results, as attention turned to how discredited officials will organise a new vote in only two month
At least 10 people have been killed in the latest clashes in drought-hit Kenya between rural communities fighting over pasture to graze their animals, police said on Monday.