An ambassador is the representative of a country sent to a different country. So Switzerland (like all other countries) has a different ambassador in each country.
Manuel Sager is the Ambassador to the US for Switzerland.
She is serving in Switzerland.
Frances E. Willis, the first female full ambassador, was first appointed as a field service officer to Switzerland in 1953 by President Dwight Eisenhower. John F. Kennedy was President when she reached the rank of full ambassador (to Ceylon) in 1962. The question is too vague to say definitively whether DDE or JFK was the one who appointed her as the first female ambassador -- DDE first appointed her, but she wasn't a full ambassador until nine years later under JFK.
Ambassador
Their husband/wife. If an ambassador is married,his/her wife/husband will not become an ambassador.
An ex-ambassador is often referred to as a former ambassador or a retired ambassador.
I believe you are thinking of an ambassador.
You would put The Ambassador of ...then what country he represents. When talking to an Ambassador , he/she are Ambassador
The full title of an ambassador is "Ambassador Extraordinary and Plenipotentiary."
If the Ambassador is currently active in the Diplomatic Service, it would be Mr. Ambassador or Madame [ Mme.] Ambassador.
The proper title for a retired ambassador is "Ambassador (Ret.)"
There is an American ambassador to Russia. The current ambassador is John Beyrle. Evidently no American can be a Russian ambassador to other countries.