MONTREAL -- Quebec authorities say they plan to pitch in on closing down the Quebec-Ontario border as of Monday, as planned under Ontario's new emergency rules.

Quebec public safety minister Genevieve Guilbault wrote on Twitter on Friday evening that she'll help "ensure tight controls on movement."

Discussions are underway between the two provincial governments to determine the terms, she wrote, but the new regime will come into place on Monday, as Ontario Premier Doug Ford directed in his announcement earlier in the day.

It's unclear if the Quebec government also intends to introduce new rules for its own citizens and visitors, or if it's merely going to help enforce Ontario's, but Guilbault said the benefits of the closure will go both ways.

"The spread of variants must be limited. It's a matter of security," she wrote.

Quebec's premier, François Legault, also posted a tweet saying that "variants have no boundaries" and that "we are all working together to break this third wave."

He said he'll continue to collaborate with Ford.

The new restrictions will limit all travel between the two provinces except for purposes of work, medical care and the transportation of goods, according to Ontario's announcement.

Later on Friday, responding to questions, Ford clarified that his government couldn't stop people from leaving Ontario, and that it would also allow people to come back over an interprovincial border if they were returning to a principal residence in Ontario, according to Ontario media.

The stretch of border between sister cities of Ottawa and Gatineau has been the trickiest, logistically speaking, to shut down and monitor, as it was last spring.

On Friday, Ottawa's police chief said it will be an expensive undertaking, with the city's mayor saying he expects the province to foot the bill.

"My initial understanding is it's intended to be on a 24-7 basis and will carry on for several weeks," said Ottawa Police Chief Peter Sloly in a Friday evening media briefing.

"It will be a significant staffing challenge for us."

Outside of Ottawa, Ontario Provincial Police will be staffing checkpoints between Ontario and Quebec through eastern Ontario and Renfrew County. It's unclear what Quebec intends its contribution to be.

CALLS FOR CLOSURE BEFORE FORD'S ANNOUNCEMENT

Before Ford's order, support was already growing in Quebec for shutting the border, or at least part of it.

Opposition party Parti Québécois called earlier Friday for roadblocks to be reinstated on the bridges between Ottawa and Gatineau in order to limit COVID-19 transmission from Ontario.

It wasn't long ago that the tables were turned, as Gatineau has been suffering from high rates of COVID-19 itself and is under special restrictions within Quebec. In late March, Legault floated the idea of shutting down the border there in order to stop Quebecers from taking advantage of Ottawa's open restaurants and other less-strict rules.

The idea has been mentioned at several other times, with Ford also threatening in December to shut down the border to prevent Quebecers from coming "in droves" to Ottawa.