The president cannot introduce a bill in Congress.

Any member of the Senate or the House of Representative can do so, except that senators cannot introduce any bill that would require anyone to pay any tax.

However, the President often asks Congress to pass some particular bill proposed by the President, and usually members of his party in Congress support the proposal and often other members do.

Occasionally the president calls a joint session of Congress (i.e. a session in which the Senate and the House of Representatives meet simultaneously in one chamber) in order to make a speech before them urging them to pass some particular article of legislation. That is what Franklin Roosevelt did on December 8, 1941, urging them to declare war against Japan, whose military had attacked the U.S. naval base at Pearl Harbor on the previous day. It is also what Dwight Eisenhower did in January 1953, when he urged them to pass legislation requiring the construction of the Interstate Highway system.