Senate Democrats said after receiving a classified briefing from the Trump administration on Tuesday that they’re increasingly concerned about the US-Israeli war on Iran dragging on “forever”—and involving American troops in a ground invasion.

“I am more fearful than ever, after this briefing, that we may be putting boots on the ground,” Sen. Richard Blumenthal (D-Conn.) told reporters, criticizing the Trump administration for not providing the American public with information that was given to senators behind closed doors.

Blumenthal’s warning came a day after Donald Trump publicly declined to rule out a ground invasion of Iran, saying he doesn’t “have the yips with respect to boots on the ground.”