President Donald Trump has said the Palestinian activist's arrest near Columbia University was the first of more to come.

Palestinan protests at Columbia University. Trump said such protests made campuses unsafe for Jewish students.

The Trump administration is employing a little-used immigration provision to try to deport a Palestinian activist with permanent residency status in the US.

If Trump is going to prevent an outcome that could result in the loss of millions of lives, it must act to contain the clash.