Nas & Kelis -- We're Trying Not to Hate Each Other's Guts

Nas & Kelis are desperately trying to bury the hatchet after their famously bitter divorce war -- in fact, they're even trying to forge a FRIENDSHIP -- and Nas tells TMZ, it's all for their son.

You'll recall, Kelis filed for divorce from Nas in April 2009 and the split was nuclear. The two warred non-stop over custody of their son and money. Kelis said when she was 7 months pregnant she was broke yet Nas refused to give her a penny -- even for medical expenses.

Now, Nas tells TMZ, the two are trying to put the past behind them in order to develop a healthy relationship for the benefit of their 3-year-old son Knight -- but they are NOT reuniting romantically.

The rapper says they've been on good terms for a while now and he hopes it will continue. Nas and Kelis even grabbed dinner last night in L.A. together.