How did President Roosevelt bypass the Neutrality Acts after Japan's invasion of China in 1937?

President Roosevelt bypassed the Neutrality Acts after Japan's invasion of China in 1937 was by continuing to supply arms to China. As Japan did not officially declare war against China, so President Roosevelt took this opportunity to continue supplying arms to China. So officially United States of America and President Roosevelt did not violet the Neutrality Act, but found a way around this act. It was a real mistake by Japan for not declaring war against China. This strategy of Japan backfired very badly. So Roosevelt did not have any problem convincing the Congress.