Nelson Mandela is criticising the US and British governments for maintaining sanctions against Libya after the conclusion of the Lockerbie trial.
Mr Mandela was instrumental in breaking the deadlock over the Lockerbie trial when he appealed to Colonel Gaddafi to allow two Libyan suspects to be extradited to the Netherlands for trial.
He said Britain and the US had agreed that sanctions would be lifted and "not merely suspended" when the suspects were handed over.
Speaking to reporters in Cape Town, Mr Mandela said he expected the West to honour that undertaking.
"They (sanctions) must be lifted. The West must not move the goal posts. For international affairs to be a success, agreements made must be honoured.
"Once an agreement has been dishonoured, it is an introduction to chaos," Mr Mandela said.
He said he planned to meet with US President George W Bush and British Prime Minister Tony Blair to persuade them to lift all sanctions against Libya.