MMDeveloper

Easy to use plugin, that blocks access to your wp-admin area by country. Uses geoip-api-php as the library to work out the visitor’s country.

Admin Block Country

It would be great to be able to redirect to a page 404

Good choice

Block access to your admin pages by country.

Markus Wiesenhofer

Polylang is a fantastic plugin to make WordPress multilingual. The Polylang extension enables you to detect the preferred language according on the country.
If your website contains 2 different locales with the same language (e.g. de_DE for German/German and de_AT for German/Austria) then Polylang automatically sets the language according to the browser settings.
Austrian website visitors who have set their operating system / browser to Germany (e.g. the Devices was buyed in Germany) will always be redirected to de_DE.
This Plugin detects the preferred language according on the visitors country and will set the language correct to de_AT.
Please notice that the IP API is only for non-commercial use allowed.
<h4>Required Plugin</h4>
<ul>
<li><a href="https://polylang.pro" rel="nofollow ugc">Polylang Pro</a> by WP SYNTEX – Polylang allows you to create a bilingual or multilingual WordPress site.</li>
</ul>

Polylang – Country Detection

This plugin detects the preferred language according on the country.

Admin Block Country vs Polylang – Country Detection