U.S. President Donald Trump's ability to swiftly impose, and then delay, tariffs on top trading partners has left world markets swinging one way and then another.

Jamieson Greer previously served as the chief of staff to the trade representative during President Donald Trump's first administration.

US President Donald Trump's trade envoy nominee Jamieson Greer told his confirmation hearing Thursday that universal tariffs were worth studying, adding that he would work to restructure global trade ties.

Jamieson Greer, President Donald Trump's nominee for U.S. trade representative, said on Thursday that a universal tariff needs further study to gauge its impact on rising U.S. trade deficits, and put countries on notice they must lower import barriers to maintain access to the U.

Jamieson Greer, President Donald Trump’s nominee to be United States trade representative, defended the use of tariffs against Mexico and Canada in his confirmation hearing on Thursday. Greer, who would play a key role in executing Trump’s trade policy,

The man likely to be named the United States' chief trade negotiator argued Thursday that President Donald Trump's tariff threat against Canada is about fentanyl trafficking.

President Donald Trump's trade envoy nominee Jamieson Greer told his confirmation hearing Thursday that universal tariffs were worth studying.