Deuteronomy 7:3-5

Don't intermarry with them -don't give your daughter to his son, and don't take his daughter for your son.

For he will turn your children away from following me in order to serve other gods. If this happens, the anger of ADONAI will flare up against you, and he will quickly destroy you.

No, treat them this way: break down their altars, smash their standing-stones to pieces, cut down their sacred poles and burn up their carved images completely.