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Mr Xi will attend two commemorative events celebrating the 20th anniversary of the establishment of diplomatic relations between Singapore and China.
He will jointly officiate the groundbreaking ceremony for the China Cultural Centre with Mr Goh and unveil the Deng Xiaoping Commemorative Marker with Minister Mentor Lee.
The above is extracted from a local newspaper. I would like to know whether 'at' in needed after 'officiate'.
Thanks in advance.
Fivejedjon's response serves for AmE as well.