”I am a candidate in the presidential election on October 12. Be sure that my determination is as great as the challenges we face”, he writes.
Biya, the world's oldest head of state, was first elected president in Cameroon in 1982. His health has often been the subject of speculation, including last year when he disappeared for 42 days before reappearing.
His time in power has been marked by allegations of corruption. Cameroon has also been forced to deal with attacks from the Islamist Boko Haram based in neighboring Nigeria, as well as a secessionist movement in the country's English-speaking provinces.
Biya has been accused of rigged elections and harsh crackdowns on the political opposition. In 2008, he secured his future in power by abolishing the law that limits the maximum number of terms for a sitting president.