No. The Senate alone votes to ratify treaties.
Congress
The President ratifies treaties after receiving the "advice and consent" of 2/3 of the Senate (not the full Congress). It is a common misunderstanding that the Senate ratifies treaties.
The Senate has the important job of approving treaties made by the president.
Treaties require consent by two-thirds of the Senate, sole executive agreements may be executed by the President acting alone.
No, it cannot. The power to make treaties with foreign countries is expressly reserved to the president under Article II of the US Constitution. The only role Congress plays is that treaties are subject to the advice and consent of the Senate. Note that "Congress", (i.e. the Senate and House of Representatives together) does not have a role in approving treaties. Only the Senate has such a role.
State governments in the United States cannot sign treaties with foreign nations. This power is reserved for the federal government under the Constitution, specifically in Article II, Section 2, which gives the President the authority to make treaties with the advice and consent of the Senate. States may enter into agreements or compacts with one another, but these must not conflict with federal law or require the consent of Congress if they involve foreign entities.
The president can make treaties, but Congress must ratify them.
Most presidential appointments, including federal judges, cabinet members and ambassadors, require a simple majority vote of the Senate. Mid-term appointments of vice presidents require a simple majority vote of both Houses of Congress, and treaties require a two-thirds majority vote of the Senate.
Article 2 section 2 of the US constitution "He shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present concur; and he shall nominate, and by and with the Advice and Consent of the Senate, shall appoint Ambassadors, other public Ministers and Consuls, Judges of the supreme Court, and all other Officers of the United States, whose Appointments are not herein otherwise provided for, and which shall be established by Law: but the Congress may by Law vest the Appointment of such inferior Officers, as they think proper, in the President alone, in the Courts of Law, or in the Heads of Departments."
Proposes laws for Congress to act onAdministers the lawsCommands all US armed forcesAppoints ambassadors and other officialsConducts foreign policyMakes treaties with the consent of the US Senatevetoes or signs bill passed by Congress
Proposes laws for Congress to act onAdministers the lawsCommands all US armed forcesAppoints ambassadors and other officialsConducts foreign policyMakes treaties with the consent of the US Senatevetoes or signs bill passed by Congress
The Congress