The UN's senior human rights officer is due to make her final address to the Human Rights Council in Geneva when it opens its eighth regular session on Monday, dpa reported.
The UN High Commissioner for Human Rights Louise Arbour announced in March she would stand down on June 30.
Her office deploys 400 human rights monitors throughout the world and, though it is independent, it works closely with the Human Rights Council.
The 61-year-old former Canadian Supreme Court justice has insisted her decision was for personal reasons. But she has been increasingly forced to defend the independence of her office against powerful groups of Islamic and African countries as well as other states that dominate the 47-member council.
The Council, which succeeded the much-criticized Human Rights Commission two years ago, is due to consider the human rights records of 32 countries including Sri Lanka, India and Britain.
They were among the first of the 192 UN members states to be subject to scrutiny under the Universal Periodic Review (UPR). The success of the mechanism is seen as a test of the Council and its integrity.
The council's eighth session will last until June 18.