As for the crisis, if you mean the refugee crisis that was present way before he became President, whilst I don't fully agree with his methods and rhetoric I do see some sense in placing a 90day stop on proceeding to allow the USA and his administration to put in place policy and processes. The current administration in Washington
That - and the entry restrictions to the USA.
It's wildly disproportionate to the real threat, endangers innocent people, excludes nations who have shown to be real threats, excludes nations in which the POTUS has commercial interests, probably endangers the lives of US civilians and service people abroad, will be used as fuel for propaganda by the very same extremists he's trying to counter, and reinforces prejudices which already exist against ethnic/religious minorities within the USA.
It is why I added "whilst I don't fully agree with his methods and rhetoric". The USA should have placed a wider moratorium in entry into the US for a period of 90 days. It should not have included re entry, or those in transit. He needs to dial back the rhetoric to remove racial slurs and scare mongering and simply state they need to review their immigration procedures and policies and need time to do that, which is reasonable as any incoming government needs time to review. I also believe that things are being overhyped by groups and individual that have interests that conflict with the current US government. I point to the not insignificant numbers of celebrities who stated they would leave the USA if Mr Trump was elected and have so far not done so. I also believe the press is overhyping things as it sells advertising space, e.g the nonsense in the press today about the utterings of a retired cold war leader warning of global war.