Sen. Chris Murphy (D-Conn.) on Tuesday defended President Obama’s decision to wait before expanding military action against the Islamic State in Iraq and Syria, saying that the terror group couldn’t be defeated in the “short term.”

“I don’t think you are going to defeat ISIS in the short term. You essentially have to dramatically weaken them and stop this perceived inevitable momentum,” Murphy said in an interview on MSNBC’s “Morning Joe.” “And so, the president is right for the time being to conduct these strikes inside Iraq that are going to substantially stop their momentum.”

Murphy, a member of the Senate Foreign Relations Committee, said the U.S. wouldn’t be able to unilaterally weaken the group and must gather support from allies.

“The only way you’re gonna stop ISIS is by rallying Sunni and Shiite regions and countries to the cause as well. So they need to be stopped, but it can’t be done by the United States alone,” he said.

{mosads}The Democrat echoed Obama’s plea for regional allies to get involved. Obama last week tasked Secretary of State John Kerry with building such a coalition. Murphy, however, expressed skepticism that U.S. allies, such as Saudi Arabia, Jordan and Egypt would intervene.

“I think it’s going to be very difficult,” Murphy said. He noted that, in some cases, it was U.S. adversaries like Iran that shared American interests and took action. 

“But this is going to be an incredibly tricky dance,” he continued. “And I think that is why the president needs to take his time here. The American public do not want us rushing into a conflict.

“If he wants to go into Syria with military power, he’s gotta come to Congress,” Murphy added.

Pressure on Obama to take aggressive military action on ISIS in Syria has been intensifying, but the president said last week the administration doesn’t have a comprehensive strategy yet. 

Critics who say Obama is not taking the threat from ISIS seriously seized on the remarks. The White House said the president was only referring to the question of expanding current strikes against ISIS in Iraq to Syria.

Over the weekend, Senate Intelligence Committee Chairwoman Dianne Feinstein (D-Calif.) said on NBC’s “Meet the Press” that the president has been “too cautious” with the U.S. response to ISIS.

Murphy dismissed that criticism.

“Yeah, I mean, I have a lot of respect for Sen. Feinstein, but I think he’s right to take his time,” he said. “We need to think first and shoot second rather than the opposite.”