A news conference scheduled for Venezuelan political activist and Nobel Peace Prize laureate Maria Corina Machado in Oslo, Norway, was canceled on Tuesday.

The anticipated afternoon event, planned on the eve of the Nobel Peace Prize award ceremony, was canceled after a delay of several hours, with no appearance by Machado, the Associated Press reported. After three hours, attendees were informed of the cancellation without explanation, with the Norwegian Nobel Institute updating guests that the press conference would “not take place today.”