OTTAWA, Aug 21 (Reuters) - Canadian Prime Minister

Justin Trudeau said on Wednesday the country's two main rail

companies and the Teamsters union had to settle their

differences at the negotiating table.

Canadian National Railway ( CNI ) and Canadian Pacific

Kansas City ( CP ) have said they will lock out their workers

early on Thursday unless new labor deals can be agreed. The two

companies have never shut down at the same time and a stoppage

could cause billions of dollars worth of economic damage.

Trudeau told reporters in Quebec that his government was

following the matter closely.

"My message is very straightforward. It is in the best

interest of both sides to continue doing the hard work at the

table to find a negotiated resolution," he said.

"Millions of Canadians, of workers, of farmers, of

businesses right across the country, are counting on both sides

to do the work and get to a resolution."

Federal Labour Minister Steven MacKinnon, who met CN

executives on Tuesday in Montreal, is due to hold talks with

CPKC in Calgary on Wednesday.