Congress
No. He can make and propose a treaty but it must be approved by congress.
2/3 of them must vote
The President is supposed to consult with the Senate
All treaties must ratified by the Senate before they take effect.
Approved by the president, ratified by the senate.
the congress must approve
Congress must also consent to the treaty.
The Congress has to agree with treaties. If they don't it cannot be made.
the Senate.
It legally binds the nations that agree to it.
2/3