(Reuters) - U.S. stock index futures edged lower on Friday as market participants continued to grapple with the ramifications of tariffs, with FedEx being the latest company to alter its full-year forecasts due to economic uncertainty. FedEx saw a 7.1% drop in premarket trading, while peer UPS slipped 1.3%.

The Federal Reserve was widely expected to leave interest rates unchanged on Wednesday, at the conclusion of its March meeting.

So far, the Federal Reserve has avoided commenting on the increasingly uncertain outlook, but investors are waiting to see whether it changes its projections on Wednesday.

U.S. stocks are drifting following signals that the U.S. economy remains solid, for the moment at least, along with reminders that big, unsettling policy changes are underway in Washington. The