We examine how U.S. monetary policy affects the international activities of U.S. banks. We access a rarely studied U.S. bank-level regulatory dataset to assess at a quarterly frequency how changes in the U.S. Federal funds rate (before the crisis) and quantitative easing (after the onset of the crisis) affect changes in cross-border claims by U.S. banks across countries, maturities and sectors, and also affect changes in claims by their foreign affiliates. We find robust evidence consistent with the existence of a potent global bank lending channel. In response to changes in U.S. monetary conditions, U.S. banks strongly adjust their cross-border claims in both the pre- and post-crisis period. However, we also find that U.S. bank affiliate claims respond mainly to host country monetary conditions.