No, it's not. Pursuant to the government's 40 years of illegal adherence to the Vienna Convention on the Law of Treaties, administrative agencies will be committed to not do anything to contravene the treaty, even with just a signature. It's "customary international law."
Like the Law of the Sea ?
The Vienna Treaty did not supercede the ratification requirements of the Constitution, period. Most other nations join a treaty when their chief executive signs it. But we do not, and the Vienna treaty did not change the very structure of the constitution.
Our Republican structure requiring Senatorial assent to the Presidents signature is still firmly in place. The rest of the world, and despotic Presidents, love to imagine that a Presidential signature binds us as it does most nations, but it certainly doesn’t.