Several prominent economists and investors have said there’s a heightened chance of a recession by 2020. Lawrence Summers, a Harvard University professor and former treasury secretary under President Bill Clinton, said this week that he thinks there’s “better than a 50/50 chance” of a recession in 2020.

Powell stressed that the Fed is “watching” the situation closely and monitoring potential cracks in the economy. His biggest concern is weakening growth in China and Europe, although he warned that a prolonged U.S. government shutdown could become a drag on the economy.

“The principal worry I would have is really global growth,” Powell said, but he added: “I still think the most likely baseline case for China is another year of solid growth.”