The Federal Open Market Committee meeting started Tuesday and will culminate with a written policy statement and press conference Wednesday—but don't expect much clarity on where interest rates are headed.

The Federal Reserve has a dual mandate of promoting maximum employment and stable prices, which it tries to foster by targeting low and stable inflation of 2%. Here's how one widely watched measure of inflation,

Tariffs make two challenges for the Fed. Uncertainty about policy may slow capital spending, pointing to lower interest rates. But tariffs will cause higher prices.