I think at the very least, we should halt all Immigration from Syria, Iraq, Afghanistan, Yemen, and Libya. However, we have to consider other nations as well. But we should definitely start with those nations.
I have a better idea..........strike down the current radical immigration policy which was adopted in 1965 --- instituted by LBJ and bring back the immigration policy we had before 1965....wherein we did not base immigration on national status but on what a person could contribute to America....aka educated immigrants, immigrants with needed skills, immigrants with similar cultural beliefs and practices, similar backgrounds etc.
In other words immigration should not be based on helping immigrants but on helping America...is dat ova your head...I bet it is.