It's more factually correct and better representative of the situation.
Just because official X said that, does not mean that the whole country is ok with him.
Citzens and politicians should be separated to keep emotions outside of this.
Let me show you two headlines here:
"Russian president declare officially a war on Ukraine"
Or
"Russia declare war on Ukraine"
Which one is more representative and more accurate of the situation?
I think you would understand my point from my example here.
You are talking about unofficial leaks?
In that case, it's even more important than any other case to seperate between officials and their countries.
"Ukrainian official had said that Ukraine have 1000 nuclear bombs'
Is unofficial statement marked clearly, on the other hand:
"Ukraine says they have 1000 nuclear bombs"
Is misleading and does not represent the situation correctly and would lead to people being misinformed about what is a leak and what is an official info.