Final answer:
President Donald Trump's administration renegotiated NAFTA, resulting in the USMCA to address trade with Canada and Mexico, including some provisions related to China's trade practices. However, no specific new agreement with another single nation is explicitly mentioned regarding Trump's recent announcement.
Step-by-step explanation:
The student asked about which country the United States, under President Donald Trump, reached a new trade agreement with. President Trump addressed China's unfair trade practices to protect America's workers and innovative industries. However, when it comes to new trade agreements, a significant development during Trump's presidency was the overhaul of the North American Free Trade Agreement (NAFTA). This resulted in creating a new agreement called the United States-Mexico-Canada Agreement (USMCA). While the question does not specify which new agreement, it is more likely referring to the USMCA as that was a substantial renegotiation affecting trade between the United States, Canada, and Mexico, introducing new regulations and requirements, such as more U.S. auto parts.
Historically, NAFTA was designed to reduce tariffs and create a large common market, which was signed by President Bush and later ratified during Clinton's presidency despite some opposition. Similar to NAFTA, USMCA aims to reduce trade barriers, although with updated provisions. Considering President Trump's active role in trade agreements and his stance on China, any recent announcement may involve USMCA or steps involving negotiations with China. Given the context provided, no specific new agreement with another nation is explicitly mentioned outside the USMCA.