OTTAWA (Reuters) -Canada's federal statistics agency said on Thursday it might have to postpone releasing September international trade data next month if the U.S. government shutdown drags on.

The last time this happened was in December 2018, when the U.S. government shutdown lasted for 35 days.

Canada exports over 70% of its merchandise south of the border, so U.S. government data on imports is required to prepare accurate trade statistics.

Statistics Canada is due to publish the next report on November 4 and will provide updates as information becomes available, the agency said in an email.

Hundreds of thousands of U.S. federal employees stopped working on October 1 when the government shut down due to a budget impasse in Congress. The shutdown, the 15th since 1981, suspended scientific research, financial oversight, environmental cleanup, collection efforts, release of statistics and a wide range of other activities.

Monthly gross domestic product data, based on industry output statistics, is not directly affected, but contingency plans are being developed to ensure that the quarterly balance of payments and GDP releases scheduled for late November proceed as planned, StatsCan said.