What did the USA do when Japan attacked China in 1937?

The United States responded to this growing threat by temporarily halting negotiations with Japanese diplomats, instituting a full embargo on exports to Japan, freezing Japanese assets in U.S. banks, and sending supplies into China along the Burma Road.

The United States responded to this growing threat by temporarily halting negotiations with Japanese diplomats, instituting a full embargo on exports to Japan, freezing Japanese assets in U.S. banks, and sending supplies into China along the Burma Road.

Explanation:

serious tone and/or informal tone