In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
In responding to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
If you have been living in Canada when you married him, then he has no right to force you to go and live in Pakistan unless you had a contractual agreement to that effect before marriage.
If you had such an agreement, then also you can insist that you would only go and live there as long as he moves there with you.
Furthermore, caring for his mother is his priority; you should gladly help him out, but he cannot expect you to do it without his help.
Almighty Allah knows best.