children with TD visa

Hi, my husband is holding TN visa and i am the spouse with TD visa, i am unemployed in US but I have applied ITIN already. We have two kids holding TD visa, this year we plan to file jointly in order to claim the Child Tax Credit, but i just found dependents must have an SSN to claim instead of ITIN. Is it true? our kids with TD visa can only apply for ITIN, does it mean we can't claim child credit?

 

If that's the case, should we file separately? as I don't see a big difference filing jointly and separately?

 

Thank you.