visiting canada without greencard but temporary I-551

[sweetgirl25180]

hi.
my parents want to visit niagara falls for 2 days.
i m a usa citizen and i put the petition for them so basically they will have a greencard in few weeks.
right now they just got the welcome notice but no greencard. i called uscis and they said that their greencard might be delayed.
so my question is that they have a temporary i-551 in their visa so can they travel to niagara falls,canada just on the passport and visa but no greencard.
i have read on canada immigration site that either they need greencard or passport with i-551.
help me guys.we are going on 4th of july.
thanks.

 

[byegeorge]

A I-551 stamp in their passports is evidence of their permanent residence status in the US and will be accepted by Canadian authorities to allow entry into Canada.

 

[sweetgirl25180]

thanks a lot.
appreciate your help.