How to lower warmongering penalty for attacking city state

[Name Lips]

It says I will suffer an "egregious" warmongering penalty. Things are going pretty well for me and I don't want to scare the other civs into attacking me. I just want to conquer a city state that's in a good spot, and is practically surrounded by my territory.

I see there are ways to lower the warmongering penalty if it's another Civ, but I don't see options for city states.

[tempest.of.emptiness]

If the city-state has a suzerain you can use a Causus Belli to declare war on that civ for a reduced penalty. The city-state will then automatically declare war. You can capture the city-state and then make peace with the civ. Do note that there is also a warmonger penalty for keeping the captured city-state.

If you have a way to goad the city-state's suzerain into declaring war on you then that's even better, because you won't have any warmonger penalty from declaring war (but still a penalty for keeping the captured city-state).