“Minus interest rates are not a policy that we are considering,” Jerome Powell, chairman of the FED said.
Powell said, “I know there are fans on the market for some negative interest rates, but it’s not the policy tool we’re considering right now.”
He explained that policy tools adopted by Fed, such as forward guidance and asset purchases, are working well for reasons that do not take into account negative interest rates, and that in the U.S., there are mixed pros and cons in terms of efficiency.

Trump Pressures to Cut Interest Rate – Against FED
"Minus interest rates are not a policy that we are considering," Jerome Powell, chairman of the FED said.