Next link contains information about google blocks: https://blog.kedare.net/blog/my-pov-on-google-cloud.html
There is message from google support ticket:
Google restricts access to some of its business services in certain countries or regions, such as Crimea, Cuba, Iran, North Korea, Sudan, and Syria.
After reviewing your case as well as our documentation, I can confirm that we block access to the Google Cloud Platform services for certain countries which includes Iran.
The decision to block or not block traffic for services for a particular country is a decision made by the US Government and interpreted by our legal team, and then implemented in our infrastructure.
Our technical troubleshooting skills do not include legal analysis and as you can visit the following URL for more information on the topic. US Department of Treasury, Iran Sanctions: