Despite their differences over the years, NeNe Leakes is letting her former 'RHOA' costar Kim Zolciak know she's got a friend in her -- especially during her divorce.

We got NeNe at LAX this week ... and she revealed to us that she and Kim ran into each other not that long ago -- noting KZ briefly mentioned she was having a hard time lately as it pertains to uncoupling with Kroy Biermann.

Check it out ... NNL says didn't elaborate on the statement .... and they kept the rest of their catch-up positive. Good to hear, considering how much they've beefed in the past.

NeNe says she wishes Kim nothing but happiness cause nobody ever wants to see a family break up ... especially when kids are involved.

Whether they choose to be together or apart, Nene says she hopes K&K can come to an amicable agreement ... cause their happiness and peace are most important.

Other than that, Nene gushes over Kim's tiny figure ... telling us she looked great -- the girl power much-welcomed after years of animosity between them.

But Kim's focus is probably geared toward her estrangement from her husband, Kroy ... rather than rebuilding her friendship with NeNe for now.

KZ & KB have been at each other's throats for months -- we broke the story ... police were called to their home in Nov following a nasty fight between them and body cam footage shows Kroy blaming Kim for their financial struggles while also accusing her of "f***ing other men."

They're still living under the same roof at their Georgia mansion ... which they're desperately trying to sell ... though they've had to slash the price a few times cause there's been no serious takers.