It's a bit more complicated than that, but as head of the Executive Branch, it is his ceremonial duty. AFTER Congress has had its say.
No, he doesn't do that. Congress does.
The United States Congress has the power to admit new states.
Congress can admit new states into the union.
Yes, the National Government can admit new states.
The United States Congress has the power to admit new states into the United States of America
Congress
It takes the President and two thirds of the Senate to concur to ratify a treaty necessary to admit a State to the Union.
Congress makes the rules to admit a new state into the Union of the United States. This is a power that is provided by the US Constitution.
National
It is in the constitution.
Only Congress can admit new States to the Union. A new state my not be created without the consent of that states legislature.
Congress. There is a process they have to do and requirements that need to be met.