Importers told government officials Monday that very little product manufacturing will return to the United States, saying Chinese manufacturers have the expertise to produce at high volume and lower prices.

The comments came as the Trump administration began public hearings on proposed tariffs on $200 billion in imports from China. While business leaders in some industries are hopeful that the tariffs will offer protection against competitors using cheaper imported Chinese goods, others worry about potential financial hardships.

More than 300 people are scheduled to testify during the six days of hearings by the U.S. Trade Representative’s Office, addressing whether the duties should be imposed and the level at which they should be set.

The hearings run through the week and conclude Aug. 27.

Administration officials say the tariffs are designed to push Beijing into talks about trade practices that the officials say discriminate against U.S. companies or allow the theft of intellectual property.