Harare - A clearly-shaky President Robert Mugabe has told President Jacob Zuma: "We are happy you are still in one piece in spite of what the papers are writing every day."Speaking at the opening of a Bi-National Commission in Harare on Thursday, the 92-year old leader told his South African counterpart: "Comrade president, we need each other even more now than before."Both leaders are facing growing calls for them to step down, Mugabe from #ThisFlag protesters and Zuma in the wake of the #StateCaptureReport.Mugabe, who has been in power since 1980, said Zimbabwe and South Africa "face renewed assaults on our independence and sovereignty".The Zimbabwe president spoke in a much weaker voice than normal and hesitated at times during his speech. There have been concerns over his health for a long time.Following a couple of embarrassing stumbles in public in recent months, cameras from the state broadcaster resolutely refuse to focus on the nonagenarian as he walks to a podium to give a speech. Thursday was no different, with the cameras fixed on the seated audience.