JOHANNESBURG — South Africa has revoked its decision to withdraw from the International Criminal Court, citing in a letter submitted to the United Nations a recent court ruling that declared the withdrawal “unconstitutional and invalid.”

It was not clear, however, if the South African statement on Tuesday meant that the country had abandoned intentions to leave the international court, or if it was seeking another way to do so.

Two other African countries, Burundi and Gambia, had announced plans to leave the court despite intense international pressure to stay, although Gambia reversed its decision last month. Supporters of the court fear that such withdrawals — especially by South Africa, one of the court’s staunchest early supporters — would lead to to an African exodus from the tribunal.

The South African government of President Jacob Zuma has long criticized the international court as being biased against African states and, in its most recent public statements, the leadership has maintained its aim to leave the organization.