"Now is the time to stop this illegal and dangerous activity," Trudeau was quoted as saying by the Associated Press.
He called the demonstrators a threat to the economy and public safety.
According to the agency, there are more than 300 trucks of the Freedom Convoy demonstrators in the center of the capital.
As Trudeau previously noted, he may use the emergency law to resolve the situation with the ongoing protests in the country against coronavirus restrictions.
On February 11, amid ongoing protests against coronavirus restrictions in Ontario, Canadian provincial premier Doug Ford declared a state of emergency in the region.
Ford called protests against coronavirus restrictions in Ottawa an "occupation".