"Announce" is a regular verb, and the past tense is "announced." For example: The president announced that he will take a trip to Canada next month.
No president in Canada.
No president in Canada.
There was no president in Canada.
Canada has no president.
No president in Canada.
No president in Canada.
No president in Canada.
No president in Canada.
There was no president in Canada.
No president in Canada.
No president in Canada.