New Balance, which has previously backed President Donald Trump’s trade policies, submitted a letter to the USTR strongly opposing President Trump’s latest threat to expand tariffs on China.

“The proposed Tranche 4 tariffs will risk our company’s overall financial health, which will in turn limit our ability to maintain and reinvest in our American factories,” said a letter submitted by New Balance to the US Trade Representative’s Office ahead of a hearing next week, according to CNN.

New Balance has long called for greater protections of U.S. manufacturing as it’s one of the few athletic footwear companies to have U.S. manufacturing. The company has five New England factories and another expected to open in 2020. But New Balance in its letter said it needs to import component parts from China that are no longer made in the U.S.

“Punitive tariffs on imports of footwear components from China will not further these important objectives, but they will threaten our ability to continue manufacturing and investing in our US footwear factories,” Monica Gorman, New Balance’s vice president of global compliance, said the letter sent to the US Trade Representative’s Office, according to a report from CNN.

New Balance will join a number of other companies opposing the proposed round of tariffs on Chinese goods at hearings in Washington D.C. this week. More than 300 company executives and trade group officials across industries are scheduled to testify.