U.S. Trade Representative Jamieson Greer will face the U.S. Senate Finance Committee on Tuesday. He is the official charged with enforcing the global tariffs Trump announced last week. This is the first time a Trump administration official has testified before Congress since announcing the tariffs. As lawmakers question the scope and duration of Trump's plan, Greer is expected to answer Republican and Democratic concerns about the tariffs. A growing number of Republicans in Congress have expressed concerns about the impact of tariffs on U.S. stock markets and global trade with allies. At least seven Republican senators have signed a bill to prevent Trump from unilaterally imposing tariffs, however, top Republican leaders have said the Senate will not consider the legislation after Trump issued a veto threat on Monday. (Kim Ten)