The cyst on Costa Rican President Oscar Arias' vocal chords will need more time to heal than doctors originally thought, according to Casa Presidencial spokeswoman Mishelle Mitchell.

After examining Arias May 21, doctors at the U.S. clinic Ear, Nose & Throat Associates in Philadelphia told the president to rest his voice for four weeks – a period that ends today. But Mitchell said Arias will need another two weeks to fully recover.

Arias is slowly taking on more responsibilities, Mitchell said. He attends the weekly cabinet meeting, and last week he formally received the new U.S. ambassador to Costa Rica, Peter Cianchette.

“When he does talk, his phrases are quite short,” Mitchell said. “You can hear him a lot better now, thank God.”

For the past five weeks, Arias has delegated most of his duties to Vice President Laura Chinchilla and to his brother, Presidency Minister Rodrigo Arias.

Last month, Chinchilla represented Arias at a summit in Peru for heads of state from Europe, Latin America and the Caribbean, and at a meeting in Brazil with regional presidents to discuss renewable energy.