Donald TrumpDonald TrumpSanders: Reinstating SALT deduction 'sends a terrible, terrible message' GOP braces for wild week with momentous vote One quick asylum fix: How Garland can help domestic violence survivors MORE said Tuesday the people fleeing violence in Syria and looking to resettle in the U.S. might include terrorists from the Islamic State in Iraq and Syria (ISIS).

"Refugees are pouring into our great country from Syria. We don't even know who they are. They could be ISIS, they could be anybody," the Republican presidential candidate said in his latest Instagram video.

"What's our president doing? Is he insane?" Trump asked.
Trump has vigorously pushed back against the relocation of the refugees, suggesting during a campaign rally Monday night they represented a "Trojan horse" for terrorists. 
Many have called for more stringent vetting of anyone allowed into the country after reports that one of the terrorists in last week's Paris attacks might slipped into Europe with Syrian refugees.
A number of Republican presidential candidates and governors have pushed back on the Obama administration's plan to relocate 10,000 Syrian refugees in the U.S. over the next year.
They are among the 85,000 refugees the U.S. plans to admit during fiscal 2016. A total of 132 settled in the U.S. last year, according to the Office of Refugee Resettlement.