"I think it's impossible to give a proper number until we understand the dimensions of the problem," the Democratic presidential contender said Sunday on NBC's "Meet the Press."
Sanders said Saudi Arabia and the United Arab Emirates should join Europe and the United States in helping to shoulder the burden of refugees driven from their war-torn countries amid the rise of ISIS -- and while he wouldn't give a number, Sanders said the United States should aid some of those refugees.
"People are leaving Iraq, they're leaving Syria, with just the clothes on their backs," he said. "The world has got to respond. The United States should be part of the response."
He's the latest Democratic contender to weigh in on the Syrian refugee crisis. Former Maryland Gov. Martin O'Malley has called for
the United States to take in as many as 65,000 refugees next year, while Hillary Clinton has issued less specific calls
for the United States to help those refugees.
President Barack Obama's administration has said it plans to accept 10,000 Syrian refugees next year.
Sanders, who calls himself a democratic socialist, has long opposed wars in the Middle East.
He said the United States must "bring the region together" -- but he called on Saudi Arabia and Turkey specifically to play larger military roles in combating ISIS.
"Countries like Saudi Arabia, which has the third largest military budget in the world, Turkey, other countries, are going to have to get their hands dirty -- going to have to get on the ground in taking on ISIS," Sanders said.
"I believe strongly the United States, the U.K., France, other countries should be supportive," he said. "But I disagree that the United States should have combat troops in that area. I fear very much that we will be in perpetual warfare in that region. I do not want to see that occur."