Mexico continues to help battle Canadian wildfires in the biggest-ever international deployment of Mexican firefighters.

The National Forestry Commission says a record 434 professional firefighters have been sent to Canada so far this year under a bilateral support agreement. The previous record was set just last year when 270 helped fight Canadian forest fires.

Canada has called for help to battle fires in Ontario, where 39 were still burning on Tuesday but were under control, and British Columbia, where more than 500 fires are still burning and a province-wide state of emergency has been declared.

Eighty-five Mexican firefighters are currently working in the central community of Fraser Lake, where three huge, raging wildfires were racing across the region earlier this week, CBC News reported.

"It's dire here right now," an official said.

Some of the Mexicans who were sent to Canada earlier have since returned home. One group, who fought fires near Renfrew, Ontario, returned with a sweet gift: hundreds of bottles of maple syrup, each one with a neck tag bearing a handwritten message saying, "Muchas gracias."