Packages coming in from (and going out) to international locations are scanned at the international sorting facilities on either coast. Depending on the class of service of your package, it may take awhile to cross the continent, especially at this time of the year, because of weather delays, Christmas shipping volume, etc.
I just had a regular priority mail package take an extra two weeks, rather than 3 days, to cross the USA for some inexplicable reason, then it was finally delivered to my customer. This almost never happens, but sometimes a parcel will disappear into a "black hole" and take some time to come out.
Hopefully your parcels will make it there in time for Christmas.