Is there any way to block international calls from a particular country (using just the country code and not the full phone number) on an Android phone?

There are several apps, see android call blocker regex .

I have not used any of them myself, so I can’t guarantee that one isn’t malicious or won’t cause problems. Look at the reviews and decide.

Actually, you can do this using the call settings in your Android phone:

1. Navigate to Settings -> Call Settings -> Call Rejection -> Auto Reject List -> Create.
2. Enter the number, or part of the number, you’d like to block (e.g. +382 for Montenegro).
3. Change Match Criteria to "begins with".
4. Hit Save.

Well if you could’nt find something “built in” than you can use some third party app from the Store

I remember using “Tru-caller” for such stuff back in the states  Though It has a paid and a free version and i used the paid one.

Call mean it is from any phone number and not from any country code.

So it is not possible to block call from country code on android phone.

But to block call from particular country by country code there are external app which claim to do so but if those are free than you get ads on your androids.

And if those calls from internet than it is difficult to block. It is better to takal them otherway. like receive call and talk long time on phone.

So they automatically stop calling you

I am sharing the app which block number

Call Blocker - Outgoing Calls - Apps on Google Play

U ca block any calls If have true caller app in that app u can block the call from any country with its pin code or any number