Depends on the state in the U.S.-and depends if you took out additional loans( and when)on the property in other states. (You need to read the whole page)In Canada mortgages are "recourse mortgages", and have been for decades. If you turn in your keys and walk away from your house, the bank will sell it for what they can get and if they don't recover the full amount of the mortgage, you will owe them the difference.
In the US in the past there were "non recourse mortgages". That means if you walked away, the bank would get what it could for the house, but you owed nothing even if it couldn't sell it for the full amount of the mortgage. That was hard on the banks.
I understood that all changed after the last housing crash. Mortgages in the US are now apparently "recourse mortgages" just like in Canada. If that's true, it will no longer be possible to just walk away. There would be ways out of the debt of course (eg repayment proposal, personal bankruptcy) but it's no longer simple.
https://www.financialsamurai.com/non-recourse-states-walk-away-from-mortgage/