Buenos Aires: United Nations Secretary-General Ban Ki-moon has indicated he may not attend the Olympic ceremony in Beijing, as the torch relay moved to Argentina on Friday.

Scheduling issues will prevent the secretary-general from attending, and his spokesoman said he will instead be on a "substantive" tour of China.

Some world leaders have said they will not attend, including British Prime Minister Gordon Brown, German Chancellor Angela Merkel and French President Nicolas Sarkozy.