In 1939, he became a Minister of Foreign Affairs. For the next two years, he tried to assure the neutrality of Romania, which was caught up between Germany and the Soviet Union. His efforts obtained guarantees from France and Great Britain, which were nevertheless not respected. After Northern Transylvania was annexed by Hungary as a result of the Second Vienna Award, and Bessarabia, Northern Bukovina, and the Hertza region were annexed by the Soviet Union in 1940, he was sent as ambassador to Moscow, where he remained until the beginning of the war against the Soviet Union on 21 June 1941. He then settled in Geneva, Switzerland.