Technically, an actual legal declaration of war requires action by Congress. But "police actions" and "emergency deployments" often can happen with only an Executive Order. The War Powers Resolution remains a Constitutional gray area.
The Legislative Branch (Congress) has the power to declare war.
the legislative branch
In the U.S., the legislative branch of government is responsible, and has the constitutional powers, to declare war.
Legislative
The Legislative Branch of government can declare war, or more specifically, Congress.congress.
"In the United States, the power to declare war and appropriate military funds lies with the legislative branch of government, but the executive branch supplies the commander in chief of the military, capable of some military actions even without an official declaration of war." Quote from Wikipedia.
It is the Legislative Branch that has the power to confirm the appointment of presidential appointments. They also have the power to declare war.
congress
The power to declare war is a power that belongs to Congress.
Congress
"In the United States, the power to declare war and appropriate military funds lies with the legislative branch of government, but the executive branch supplies the commander in chief of the military, capable of some military actions even without an official declaration of war." Quote from Wikipedia.
In the United States, the power to declare war is primarily vested in Congress, which is the legislative branch of the federal government. The Constitution grants Congress the authority to declare war, while the President, as the Commander-in-Chief of the armed forces, has the power to direct military operations. However, the President cannot officially declare war without Congressional approval. This division of powers is designed to ensure a system of checks and balances between the branches of government.