VANCOUVER (Reuters) - Long delays were reported at the Canadian-U.S. border on Monday as Ottawa finally opened doors to fully vaccinated American tourists for the first time in 16 months, causing a rush of tourists to travel north during the busy summer season.

       Government data showed a seven-hour wait time for the Fort Frances, Ontario, and International Falls, Minnesota, crossing. Fort Frances advertises itself online as "rarely experiencing delays".

       Several crossings in Ontario and New Brunswick - between the states of New York and Maine - had waits of three hours.

       Canada barred all leisure travel from the United States in March 2020 due to the COVID-19 pandemic, but as of August 9 fully vaccinated travelers are able to enter the country. International travelers who are fully vaccinated will be allowed to enter in early September.

       Late on Friday, the Canadian government and border staff reached a tentative deal to end a strike action that began earlier in the day.

       Prior to the pandemic, tourism was the fifth-largest industry in Canada, contributing C$105 billion ($83.4 billion) to the GDP and providing one in ten jobs, according to the Tourism Industry Association of Canada.

       Toronto's Pearson International Airport, Canada's biggest airport, has also asked travelers to brace for delays as American leisure travelers returns to Canada.

       (Reporting by Moira Warburton in Vancouver; Editing by Angus MacSwan)