The U.S. Federal Aviation Administration warned airlines on Friday to exercise caution when flying over Mexico, Central America and parts of South America, citing the risks of potential military activities and GPS interference. The FAA said it had issued Notices to Airmen covering Mexico and Central American countries, as well as Ecuador, Colombia and portions of airspace within the eastern Pacific Ocean. The warnings began on Friday and will last 60 days, it said. Tensions between the U.S. and regional leaders have ramped up since the Trump administration mounted a large-scale military buildup in the southern Caribbean, attacked Venezuela and...