The unexpected freeze of international humanitarian aid by the United States is causing additional suffering to the most vulnerable, says the international humanitarian organization Doctors without Borders (MSF). "Working in various parts of the worldhere humanitarian aid is vital, Doctors without Borders sees that the unexpected freeze of international aid is causing additional suffering to the most vulnerable. The speed with which health services have been affected has not given patients and health workers enough time to adapt," MSF told the Interfax-Ukraine agency.