The Italian Mathematical Union (Unione Matematica Italiana) shares the concerns expressed by Professor Pavel Exner, President of the European Mathematical Society, about the decision taken by the US administration of temporarily suspending travels to the US from seven countries (see http://www.euro-math-soc.eu/news/17/01/31/ems-president-trumps-executive-order).
As Prof. Exner pointed out, such policies may jeopardize the atmosphere of international collaboration that  science needs for its development.
Professor Ciro Ciliberto
President of the Unione Matematica Italiana