Laurence D. Fink, chief executive officer of BlackRock Inc. said there are indications that the U.S. economy is slowing as businesses weigh whether the Trump administration will be able to pass tax reform and an infrastructure program quickly.

“The warning signs are getting darker,” said Fink, in an interview Wednesday on Bloomberg Television.

Fink, who runs the world’s largest money manager, mentioned a pullback in car sales and a pause in merger and acquisition activity as indications that uncertainty is rising.

The stock market needs validation that U.S. corporate earnings will stay strong and that the policies of President Donald Trump will move forward in Congress in order to move higher, Fink said.

BlackRock reported first-quarter results earlier Wednesday that beat analysts’ estimates on earnings while missing on revenue.

Outside the U.S., Fink said he’s taking a “wait-and-see” approach to Brexit because it’s unclear what the change will mean for