They are OK if people understand the abbreviations. I would have only understood the first.
Interested in Language
Is it correct to say "RF (Russian Federation) President Vladimir Putin or RA (Republic of Armenia) President Serzh Sargsyan?
No. Use the full name first, then give the abbreviation in parentheses. Later uses in the same text can just use the abbreviation.
Correct. If you are sure that your audience will understand your abbreviations, then you do not need to define them at first use.
If unsure, then define them as I said.