(CNN) -- Brazil's Foreign Minister has resigned from his post, citing health problems and upcoming medical treatments as the main reasons.
In a letter to Brazilian President Michel Temer, Foreign Minister Jose Serra said he was "saddened" to be stepping down but said his doctors told him he would need "at least four months" to properly recover.
The letter was handed in personally to Temer on Wednesday, and published by state-run news agency Agencia Brasil.
Serra, 74, a career politician, had been in the job for less than a year.
He took office after former president Dilma Rousseff was suspended in May last year during the investigation that lead to her impeachment. She was ultimately ousted from office in August 2016.
His political career began in 1995, when he served as Planning Minister for former president Fernando Henrique Cardoso. He's also been senator, governor and mayor of Sao Paulo.
In 2010, he ran for president but lost against Rousseff, who was elected as Brazil's first female president that year.
Neither Temer's office, nor the foreign ministry have confirmed who will be replacing Serra.
CNNE's Abel Alvarado in Atlanta and Euan McKirdy in Hong Kong contributed to this report.
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