It is likely to stoke tensions between Europe and the US, which regulates the tech industry with a lighter hand and has complained that the European Union is singling out American companies for punishment.
To Trump, the fine appeared to serve as the latest evidence of Europe's exploitation of the United States on a variety of matters, including trade and nations' contributions to defense spending, and it came a day after he threatened "tremendous retribution", particularly on European-made cars, if the EU doesn't change its trade policies.
The president is due to conduct crunch talks with European Commission President Jean-Claude Juncker at the White House next week, where he could choose to bring up the Google fine again.
Google has been given 90 days to cease all illegal practices or face additional fines of up to 5% of Google parent company Alphabet's global turnover.
Mr Pichai said: "The free distribution of the Android platform, and of Google's suite of applications, is not only efficient for phone makers and operators-it's of huge benefit for developers and consumers".
Google also reportedly forces smartphone makers to integrate its own apps to their phones, should they wish to offer the Google Play Store on them. It's still early to tell how the Internet search giant will respond to the ruling, but many observers have been quick to point out that Sundar Pichai's memo contains what could be constituted as "warning shots" regarding the openness of Android.
After all, if Google can't rely on the revenue stream from Android, that could mean that device manufacturers might, down the line, be faced with paying for Android service - costs that could make for more expensive phones for users.
The Commission opened its investigation into Android following a 2013 complaint from lobbying group FairSearch, which was backed by competitors including Oracle, Nokia and Microsoft.
In its ruling, the European Union said Google broke the rules by requiring cellphone makers to take a bundle of Google apps if they wanted any at all.