Ecuador's Ambassador to the UK Ana Alban says she intends to appeal to the Home Office for Julian Assange to be granted safe passage to medical services for treatment.
Ms Alban told an Ecuadorian government newspaper that Mr Assange currently requires constant medical attention at his refuge inside the Ecuadorian embassy in London.
"In regard to how he is doing, what I can say is, imagine how well someone is in a space of 50 square metres without much sun and poor air circulation," said Ms Alban.
"He is not sick but he has a chronic lung condition that could lead to complications. In the northern hemisphere we are entering winter. And, we have a long winter ahead of us, cold and with few daylight hours.
"As a result, whatever symptoms he is currently suffering from could get worse during this period," she added.
Assange, 41, whose Wikileaks website angered the United States by releasing thousands of secret diplomatic cables, has been holed up inside Ecuador's embassy in London since June to avoid extradition to Sweden for questioning over rape and sexual assault allegations. Assange has denied any wrongdoing.
Read more on this: What are Julian Assange's options out of the diplomatic impasse?
British authorities say Assange will be arrested if he sets foot outside the embassy. The building, located just behind London's famed Harrods department store, is under constant police surveillance.
Ecuador said in October it is worried about Assange's health and asked Britain to guarantee him safe passage to hospital from the embassy if he needs medical treatment.