President Cyril Ramaphosa said his apology to Zimbabweans over the weekend was necessary after xenophobic attacks over the last two weeks tarnished South Africa's international reputation."Our image, our standing and our integrity was negatively affected. We will have to work very hard as South Africans to regain our stature, our position and in this regard, it was best to stand up and say we are sorry for what happened," he said on Monday.Ramaphosa was speaking at the SA Clothing and Textile Workers' Union's (Sactwu) 14th national congress at the International Convention Centre in Durban.READ | 'Grass is greener in SA', says foreign national as many ready for return to Katlehong after xenophobia attacksOver the weekend, he was booed while delivering a speech at a memorial for former Zimbabwean president Robert Mugabe in Harare."The people of Zimbabwe, almost in unison, expressed their disappointment, unhappiness and anger at us as South Africans. They saw me as representing all of us in SA. Their reaction was against us as the whole stadium full of 40 000 people booed me," he told more than 1 000 Sactwu delegates.Higher standardHe said Zimbabweans only accepted him after he offered an apology."It was only when I said I regret what is happening in our country and offered an apology on behalf of all of us as SA - that is when they responded positively in accepting that apology. I have apologised on your behalf and I hope that will sink into our consciousness."He added: "The world expects us to behave in a way where we respect the rights of people from other nations."READ | 'Nigerians overreacted over xenophobia' - SA tells special envoyRamaphosa said the world expected a higher standard from South Africa."It is so because the world has put us on a much higher pedestal. They know we are a nation with possibly the best Constitution in the world; a Constitution that enshrines the rights of everyone. They also know we have a Freedom Charter which we adopted."He said other African countries were in disbelief at the xenophobia in SA."When they saw what was happening… they were really shocked. They were shocked and taken aback."