The White House on Monday said Iran was in some cases “actively facilitating” rocket and drone attacks by Iranian-backed proxy groups on U.S. military bases in Iraq and Syria, and President Biden has directed the Department of Defense to brace for more and respond appropriately.

White House spokesman John Kirby said there had been an uptick in such attacks over the last week, and especially over the last few days, but the U.S. would not allow its interests in the region to “go unchallenged.”

He said the United States believed these groups were supported by Iran’s Islamic Revolutionary Guard (IRGC) and the Iranian government, which was also continuing to support the Hamas and Hezbollah militant groups.