The mother of a US citizen sentenced to prison in Iran said on Tuesday that her son has lost his appeal, and that she is disappointed that President Donald Trump did not mention his case during a speech at the United Nations General Assembly. Michael R. White, 46, a former US Navy cook, is sentenced to 10 years in prison and was the first American known to be arrested in Iran after Mr Trump took office. Mr White is thought to have been detained in July last year and it is not know what charges he was found guilty of. He had been visiting his girlfriend in Iran – it was his fifth or sixth visit – and was due to return home via Dubai. His mother filed a missing person report with the State Department after he did not board the flight. Iranian officials said he was detained in the city of Mashhad, in the north-east of the country. The US and Iran do not maintain diplomatic relations, and communications between the two nations are passed along by Swiss diplomats. A family spokesperson speaking on behalf of Mr White's mother, Joanne White, said she has not had any way to communicate with her son, <em>The New York Times </em>reported. She relies on information from Swiss officials, who meet him when possible. "I think her feeling is it is now time for his case to get as much attention as those in which the president has successfully brought people home," the spokesperson said. Mr White’s health is also a concern, with reports that he has recently had surgery for melanoma. His family say he suffers from acute asthma and shortly before he was arrested he underwent chemotherapy for a neck tumour. At least three other US citizens are being held in Iran, and one US man has been missing in Iran for over a decade. Earlier on Tuesday, Mr Trump delivered a speech at UNGA, where he warned Iran to end its aggression in the Middle East or face the prospect of tougher economic sanctions. There was no mention of the detained US citizens, however, speaking on the sidelines of the session, <a href="https://www.thenational.ae/world/mena/relatives-of-jailed-dual-nationals-call-on-leaders-to-put-pressure-on-iran-1.914647">relatives of dual nationals incarcerated in Iranian</a> called on their governments to declare a hostage crisis with the country. Richard Ratcliffe, the husband of the British-Iranian woman Nazanin Zaghari-Ratcliffe, said that Iran hides behind its justice system to cast doubt on the cases the families raise.