(CNN) –– President Donald Trump’s US Trade Representative Jamieson Greer on Tuesday defended the administration’s expansive tariffs during a routine hearing before the Senate Finance Committee.

“Last Wednesday, President Trump declared a national emergency in response to the large and persistent trade deficit that has built up in recent years,” Greer said in his prepared remarks. “This deficit is driven in part by non- reciprocal tariffs, trading barriers, and other economic policies pursued by our foreign trading partners. President Trump imposed tariffs to address this emergency.”

Greer then said the president’s “strategy is already bearing fruit” and that nearly “50 countries have approached me to discuss the President’s new policy and explore how to achieve reciprocity.”

This story is developing and will be updated.