All of the examples you cite allow for abortions in only limited circumstances. In the US, it is possible to have abortions for elective reasons. The two are not comparable.
The argument you made was "The US is one of only three countries that allow for abortions past 24 weeks", which I have proven is incorrect. Further, if you now want to make the argument that (some states in) the US, China and North Korea are the only places which allow for elective abortion past 24 weeks, then that is incorrect too, as you can see from the quote I provided above for Canada.
You are referring to edge cases.
And again, the argument you made was that you "really don't see any valid argument as to why late-term abortions should be allowed". I provided a valid argument. Of course they are edge cases: Global data show that somewhere around 1% of abortions take place beyond 20 weeks and fewer than 0.1% beyond 24 weeks.