How to make screeded floor smooth enough to take sticky vinyl tiles?

Can anyone suggest what product would make a screeded concrete floor smooth enough so that self-adhesive vinyl tiles will stick? I wondered about using an oilbased floor paint, but I imagine a 2-part resin of some kind might work better, as it could be poured on thickly to achieve a truly smooth finish. Can anyone recommend anything?
The room I want to do is only a small 5ft x 5ft approx loo. The screeded floor is very dry; there is no dampness there.
Many thanks
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