I'm in the process of negotiating a move from a UK subsidiary to US head office, based in Pennsylvania. 

An element of my potential new employment that concerns me, is that it is 'at-will'. This is not something that I'm familiar with - I am used to the protections provided by UK Employment Law. 

My visa would be tied to being employed by this specific company - I would have to leave the US if they chose to terminate my employment - potentially without the company covering the costs of my return to the UK.

**First, would it be *possible* (in a legal sense) for my employer not to employ me at-will and what would I expect them to provide me to make that happen?**

**Second, is there a specific alternative I can bring to my employer to make this request reasonable and simple for them to enact?**