U.S. President Donald Trump has threatened new tariffs on eight European countries related to the Greenland dispute, causing declines in major European stock indices. The Euro Stoxx 50 fell 1.7%, Germany's DAX dropped 1.3%, and other key markets like the UK's FTSE 100 and France's CAC 40 also saw losses. This move has triggered market concern over escalating trade tensions between the U.S. and Europe.